diff --git a/sardine/UserConfig.py b/sardine/UserConfig.py
index ed694ab9..2dc37214 100644
--- a/sardine/UserConfig.py
+++ b/sardine/UserConfig.py
@@ -1,7 +1,6 @@
 import json
 from dataclasses import dataclass
 from pathlib import Path
-from typing import Union
 
 from appdirs import *
 from rich import print
@@ -48,7 +47,7 @@ def _recursive_update(dest: dict, src: dict):
 
 @dataclass
 class Config:
-    midi: Union[str, None]
+    midi: str | None
     beats: int
     parameters: list
     bpm: int
diff --git a/sardine_core/base/clock.py b/sardine_core/base/clock.py
index 872a064f..11a199f3 100644
--- a/sardine_core/base/clock.py
+++ b/sardine_core/base/clock.py
@@ -1,6 +1,6 @@
 import math
 from abc import ABC, abstractmethod
-from typing import Optional, Union
+from typing import Optional
 
 from .runner import BaseRunnerHandler
 
@@ -191,7 +191,7 @@ def can_sleep(self) -> bool:
 
     def get_beat_time(
         self,
-        n_beats: Union[int, float],
+        n_beats: int | float,
         *,
         time: Optional[float] = None,
         sync: bool = True,
@@ -199,7 +199,7 @@ def get_beat_time(
         """Determines the amount of time to wait for N beats to pass.
 
         Args:
-            n_beats (Union[int, float]): The number of beats to wait for.
+            n_beats (int | float): The number of beats to wait for.
             time (Optional[float]):
                 The exact time to use for calculations.
                 If not provided, this defaults to `shifted_time`.
@@ -237,7 +237,7 @@ def get_beat_time(
 
     def get_bar_time(
         self,
-        n_bars: Union[int, float],
+        n_bars: int | float,
         *,
         time: Optional[float] = None,
         sync: bool = True,
@@ -245,7 +245,7 @@ def get_bar_time(
         """Determines the amount of time to wait for N bars to pass.
 
         Args:
-            n_bars (Union[int, float]): The number of bars to wait for.
+            n_bars (int | float): The number of bars to wait for.
             time (Optional[float]):
                 The exact time to use for calculations.
                 If not provided, this defaults to `shifted_time`.
@@ -261,7 +261,7 @@ def get_bar_time(
         """
         return self.get_beat_time(n_bars * self.beats_per_bar, time=time, sync=sync)
 
-    async def sleep(self, duration: Union[float, int]) -> None:
+    async def sleep(self, duration: float | int) -> None:
         """Sleeps for the given duration.
 
         This method can be optionally overridden by subclasses.
diff --git a/sardine_core/clock/internal_clock.py b/sardine_core/clock/internal_clock.py
index 7ed28800..b825f236 100644
--- a/sardine_core/clock/internal_clock.py
+++ b/sardine_core/clock/internal_clock.py
@@ -1,11 +1,10 @@
 import asyncio
 import math
 import time
-from typing import Union
 
 from sardine_core.base import BaseClock
 
-NUMBER = Union[int, float]
+NUMBER = int | float
 
 __all__ = ("InternalClock",)
 
@@ -132,7 +131,7 @@ def tempo(self, new_tempo: NUMBER):
 
     ## METHODS  ##############################################################
 
-    async def sleep(self, duration: Union[float, int]) -> None:
+    async def sleep(self, duration: NUMBER) -> None:
         return await asyncio.sleep(duration)
 
     async def run(self):
diff --git a/sardine_core/clock/link_clock.py b/sardine_core/clock/link_clock.py
index 24102410..4387cbf0 100644
--- a/sardine_core/clock/link_clock.py
+++ b/sardine_core/clock/link_clock.py
@@ -1,10 +1,10 @@
-from typing import Optional, Union
+from typing import Optional
 
 import link
 
 from sardine_core.base import BaseClock, BaseThreadedLoopMixin
 
-NUMBER = Union[int, float]
+NUMBER = int | float
 
 __all__ = ("LinkClock",)
 
diff --git a/sardine_core/fish_bowl.py b/sardine_core/fish_bowl.py
index 55281ec1..ba0ef8c0 100644
--- a/sardine_core/fish_bowl.py
+++ b/sardine_core/fish_bowl.py
@@ -1,6 +1,6 @@
 import asyncio
 import collections
-from typing import Hashable, Iterable, Optional, Protocol, Union
+from typing import Hashable, Iterable, Optional, Protocol
 
 from exceptiongroup import BaseExceptionGroup
 
@@ -77,7 +77,9 @@ def __repr__(self) -> str:
         status = (
             "playing"
             if running and not paused
-            else "paused" if running and paused else "stopped"
+            else "paused"
+            if running and paused
+            else "stopped"
         )
 
         return "<{} {} clock={!r}>".format(
@@ -164,14 +166,14 @@ def is_running(self):
 
     ## SLEEPING MANAGEMENT ############################################################
 
-    async def sleep(self, duration: Union[int, float]):
+    async def sleep(self, duration: int | float):
         """Sleeps for the given duration.
 
         This method is simply a shorthand for `self.sleeper.sleep(duration)`.
         """
         return await self.sleeper.sleep(duration)
 
-    async def sleep_beats(self, beats: Union[int, float]):
+    async def sleep_beats(self, beats: int | float):
         """Sleeps for the given number of beats."""
         return await self.sleep(beats * self.clock.beat_duration)
 
diff --git a/sardine_core/handlers/midi_in.py b/sardine_core/handlers/midi_in.py
index 1b3891b0..73e5cfc5 100644
--- a/sardine_core/handlers/midi_in.py
+++ b/sardine_core/handlers/midi_in.py
@@ -1,7 +1,7 @@
 import sys
 from collections import deque
 from dataclasses import dataclass
-from typing import Optional, Union
+from typing import Optional
 
 import mido
 from mido import Message, get_input_names, open_input, parse_string_stream
@@ -99,7 +99,7 @@ def _push_message_to_dict(index: str, message: mido.Message) -> None:
                 # Case where the message is just garbage to dispose of
                 return
 
-    def _extract_value(self, message: Union[mido.Message, None]) -> Union[Message, int]:
+    def _extract_value(self, message: mido.Message | None) -> Message | int:
         """
         Given a mido.Message, extract needed value based on message type
         """
diff --git a/sardine_core/handlers/missile.py b/sardine_core/handlers/missile.py
index 803cc950..6a509095 100644
--- a/sardine_core/handlers/missile.py
+++ b/sardine_core/handlers/missile.py
@@ -1,5 +1,5 @@
 import asyncio
-from typing import Optional, Union
+from typing import Optional
 
 from sardine_core.base import BaseHandler
 
@@ -9,7 +9,7 @@
 class MissileMode(BaseHandler):
     """Maximize the current thread's wake time with a CPU-intensive task."""
 
-    def __init__(self, *, burn_rate: Union[float, int] = 1000):
+    def __init__(self, *, burn_rate: float | int = 1000):
         super().__init__()
         self.burn_interval = 1 / burn_rate
         self._running = False
diff --git a/sardine_core/handlers/osc_in.py b/sardine_core/handlers/osc_in.py
index d43143be..ae0f509d 100644
--- a/sardine_core/handlers/osc_in.py
+++ b/sardine_core/handlers/osc_in.py
@@ -1,4 +1,4 @@
-from typing import Any, Callable, Optional, Union
+from typing import Any, Callable, Optional
 
 from osc4py3.as_eventloop import *
 from osc4py3.oscchannel import TransportChannel, get_channel
@@ -109,7 +109,7 @@ def event_dispatcher(address, *args) -> None:
 
         osc_method(address, event_dispatcher, argscheme=OSCARG_DATA)
 
-    def get(self, address: str) -> Union[Any, None]:
+    def get(self, address: str) -> Any | None:
         """Get a watched value. Return None if not found"""
         try:
             return self._watched_values[address]
diff --git a/sardine_core/handlers/sender.py b/sardine_core/handlers/sender.py
index 3db6c9c9..88d08d3b 100644
--- a/sardine_core/handlers/sender.py
+++ b/sardine_core/handlers/sender.py
@@ -1,7 +1,7 @@
 import asyncio
 from math import floor
 from random import random
-from typing import Any, Callable, Generator, Optional, ParamSpec, TypeVar, Union
+from typing import Any, Callable, Generator, Optional, ParamSpec, TypeVar
 
 from sardine_core.base import BaseHandler
 from sardine_core.sequences import euclid
@@ -12,14 +12,14 @@
 P = ParamSpec("P")
 T = TypeVar("T")
 
-Number = Union[float, int]
+Number = float | int
 ReducedElement = TypeVar("ReducedElement")
-RecursiveElement = Union[ReducedElement, list]  # assume list is list[RecursiveElement]
-ParsableElement = Union[RecursiveElement, str]
+RecursiveElement = ReducedElement | list  # assume list is list[RecursiveElement]
+ParsableElement = RecursiveElement | str
 
 # Sub-types of ParsableElement
-NumericElement = Union[Number, list, str]
-StringElement = Union[str, list]  # assume list is list[StringElement]
+NumericElement = Number | list | str
+StringElement = str | list  # assume list is list[StringElement]
 
 Pattern = dict[str, list[ParsableElement]]
 ReducedPattern = dict[str, ReducedElement]
diff --git a/sardine_core/handlers/sleep_handler/__init__.py b/sardine_core/handlers/sleep_handler/__init__.py
index 2efd04a3..0c1d69df 100644
--- a/sardine_core/handlers/sleep_handler/__init__.py
+++ b/sardine_core/handlers/sleep_handler/__init__.py
@@ -1,7 +1,7 @@
 import asyncio
 import heapq
 from collections import deque
-from typing import Optional, Union
+from typing import Optional
 
 from exceptiongroup import BaseExceptionGroup
 
@@ -11,7 +11,7 @@
 
 __all__ = ("SleepHandler", "TimeHandle")
 
-NUMBER = Union[float, int]
+NUMBER = float | int
 
 
 class SleepHandler(BaseHandler):
diff --git a/sardine_core/handlers/superdirt.py b/sardine_core/handlers/superdirt.py
index dfc53c5a..079bac85 100644
--- a/sardine_core/handlers/superdirt.py
+++ b/sardine_core/handlers/superdirt.py
@@ -1,6 +1,6 @@
 import time
 from itertools import chain
-from typing import Any, Callable, List, Optional, Union
+from typing import Any, Callable, List, Optional
 
 from osc4py3 import oscbuildparse
 from osc4py3.as_eventloop import osc_send, osc_udp_client
@@ -159,14 +159,15 @@ def rename_keys(initial_dictionary: dict, aliases: dict) -> dict:
     @alias_param(name="rate", alias="r")
     def send(
         self,
-        sound: Union[
+        sound: Optional[StringElement | List[StringElement]]
+        | Callable[
+            [],
             Optional[StringElement | List[StringElement]],
-            Callable[[], Optional[StringElement | List[StringElement]]],
         ],
-        orbit: Union[NumericElement, Callable[[], NumericElement]] = 0,
-        iterator: Union[Number, Callable[[], Number]] = 0,
-        divisor: Union[NumericElement, Callable[[], NumericElement]] = 1,
-        rate: Union[NumericElement, Callable[[], NumericElement]] = 1,
+        orbit: NumericElement | Callable[[], NumericElement] = 0,
+        iterator: Number | Callable[[], Number] = 0,
+        divisor: NumericElement | Callable[[], NumericElement] = 1,
+        rate: NumericElement | Callable[[], NumericElement] = 1,
         **pattern: ParsableElement,
     ):
         if sound is None:
diff --git a/sardine_core/io/UserConfig.py b/sardine_core/io/UserConfig.py
index 537ad312..6cd8ca72 100644
--- a/sardine_core/io/UserConfig.py
+++ b/sardine_core/io/UserConfig.py
@@ -1,7 +1,6 @@
 import json
 from dataclasses import dataclass
 from pathlib import Path
-from typing import Union
 
 from appdirs import *
 
@@ -50,7 +49,7 @@ def _recursive_update(dest: dict, src: dict):
 
 @dataclass
 class Config:
-    midi: Union[str, None]
+    midi: str | None
     beats: int
     bpm: int
     debug: bool
diff --git a/sardine_core/run.py b/sardine_core/run.py
index bd990afd..77441b0b 100644
--- a/sardine_core/run.py
+++ b/sardine_core/run.py
@@ -4,7 +4,7 @@
 from itertools import product
 from pathlib import Path
 from string import ascii_lowercase, ascii_uppercase
-from typing import Any, Callable, Optional, ParamSpec, TypeVar, Union, overload
+from typing import Any, Callable, Optional, ParamSpec, TypeVar, overload
 
 from ziffers import z
 
@@ -158,7 +158,7 @@ def wrapper(*args: ParamSpec.args, **kwargs: ParamSpec.kwargs) -> T:
 
 @overload
 def swim(
-    func: Union[Callable[ParamSpec, Any], AsyncRunner],
+    func: Callable[ParamSpec, Any] | AsyncRunner,
     /,
     # NOTE: AsyncRunner doesn't support generic args/kwargs
     *args: ParamSpec.args,
@@ -174,13 +174,13 @@ def swim(
     quant: Quant = "bar",
     until: Optional[int] = None,
     **kwargs,
-) -> Callable[[Union[Callable, AsyncRunner]], AsyncRunner]: ...
+) -> Callable[[Callable | AsyncRunner], AsyncRunner]: ...
 
 
 # FIXME: quant docstring is outdated
 # pylint: disable=keyword-arg-before-vararg  # signature is valid
 def swim(
-    func: Optional[Union[Callable, AsyncRunner]] = None,
+    func: Optional[Callable | AsyncRunner] = None,
     /,
     *args,
     quant: Quant = "bar",
@@ -193,7 +193,7 @@ def swim(
     declared and followed by the scheduler system to recurse in time if needed.
 
     Args:
-        func (Optional[Union[Callable[P, T], AsyncRunner]]):
+        func (Optional[Callable[P | T], AsyncRunner]]):
             The function to be scheduled. If this is an AsyncRunner,
             the current state is simply updated with new arguments.
         *args: Positional arguments to be passed to `func.`
@@ -213,8 +213,7 @@ def swim(
         **kwargs: Keyword arguments to be passed to `func.`
     """
 
-    def decorator(func: Union[Callable, AsyncRunner], /) -> AsyncRunner:
-
+    def decorator(func: Callable | AsyncRunner, /) -> AsyncRunner:
         # This is true when the function is already running on the scheduler
         if isinstance(func, AsyncRunner):
             func.update_state(*args, **kwargs)
@@ -277,7 +276,7 @@ def again(runner: AsyncRunner, *args, **kwargs):
     runner.reload()
 
 
-def die(func: Union[Callable, AsyncRunner]) -> AsyncRunner:
+def die(func: Callable | AsyncRunner) -> AsyncRunner:
     """
     Swimming decorator: remove a function from the scheduler. The function
     will not be called again and will likely stop recursing in time.
@@ -295,7 +294,7 @@ def die(func: Union[Callable, AsyncRunner]) -> AsyncRunner:
     return runner
 
 
-def sleep(n_beats: Union[int, float]):
+def sleep(n_beats: int | float):
     """Artificially sleep in the current function for `n_beats`.
 
     Example usage: ::
@@ -444,7 +443,7 @@ class Delay:
     extra indentation for marking visually where sleep takes effect.
     """
 
-    def __init__(self, duration: Union[int, float] = 1, delayFirst: bool = True):
+    def __init__(self, duration: int | float = 1, delayFirst: bool = True):
         self.duration = duration
         self.delayFirst = delayFirst
 
diff --git a/sardine_core/scheduler/async_runner.py b/sardine_core/scheduler/async_runner.py
index a3f1010f..e0eb0c45 100644
--- a/sardine_core/scheduler/async_runner.py
+++ b/sardine_core/scheduler/async_runner.py
@@ -6,7 +6,7 @@
 import traceback
 from collections import deque
 from dataclasses import dataclass
-from typing import TYPE_CHECKING, Any, MutableSequence, NamedTuple, Optional, Union
+from typing import TYPE_CHECKING, Any, MutableSequence, NamedTuple, Optional
 
 from rich.panel import Panel
 
@@ -50,7 +50,7 @@ def _discard_kwargs(sig: inspect.Signature, kwargs: dict[str, Any]) -> dict[str,
 
 def _extract_new_period(
     sig: inspect.Signature, kwargs: dict[str, Any], default_period: int | float
-) -> Union[float, int]:
+) -> float | int:
     period = kwargs.get("p")
 
     # Assign a default period if necessary
@@ -104,7 +104,7 @@ class FunctionState:
 
 
 class DeferredState(NamedTuple):
-    deadline: Union[float, int]
+    deadline: float | int
     index: int
     state: FunctionState
 
@@ -187,7 +187,7 @@ class AsyncRunner:
     running at different phases. To synchronize these functions together,
     their interval shifts should be set to the same value (usually 0).
     """
-    snap: Optional[Union[float, int]]
+    snap: Optional[float | int]
     """
     The absolute time that the next interval should start at.
 
@@ -361,7 +361,7 @@ def push(self, func: "MaybeCoroFunc", *args, **kwargs):
         self.states.append(new_state)
 
     def push_deferred(
-        self, deadline: Union[float, int], func: "MaybeCoroFunc", *args, **kwargs
+        self, deadline: float | int, func: "MaybeCoroFunc", *args, **kwargs
     ):
         """Adds a function to a queue to eventually be run.
 
@@ -372,7 +372,7 @@ def push_deferred(
         priority and replace the `snap` attribute to ensure they run on time.
 
         Args:
-            time (Union[float, int]):
+            time (float | int):
                 The absolute clock time to wait before the function state
                 is pushed.
             func (MaybeCoroFunc): The function to add.
@@ -481,7 +481,7 @@ def allow_interval_correction(self) -> None:
         """Allows the interval to be corrected in the next iteration."""
         self._can_correct_interval = True
 
-    def delay_interval(self, deadline: Union[float, int], period: Union[float, int]):
+    def delay_interval(self, deadline: float | int, period: float | int):
         """Delays the next iteration until the given deadline has passed.
 
         This is equivalent to setting the runner's `snap` attribute
@@ -496,8 +496,8 @@ def delay_interval(self, deadline: Union[float, int], period: Union[float, int])
         to skip the current iteration.
 
         Args:
-            time (Union[float, int]): The absolute time to wait.
-            period (Union[float, int]): The period to synchronize to.
+            time (float | int): The absolute time to wait.
+            period (float | int): The period to synchronize to.
 
         Raises:
             RuntimeError: A function must be pushed before this can be used.
@@ -510,7 +510,7 @@ def _check_snap(self, time: float) -> None:
         if self.snap is not None and time + self._last_interval >= self.snap:
             self.snap = None
 
-    def _correct_interval(self, period: Union[float, int]) -> None:
+    def _correct_interval(self, period: float | int) -> None:
         """Checks if the interval should be corrected.
 
         Interval correction occurs when `allow_interval_correction()`
@@ -519,7 +519,7 @@ def _correct_interval(self, period: Union[float, int]) -> None:
         did not change, interval correction must be requested again.
 
         Args:
-            period (Union[float, int]):
+            period (float | int):
                 The period being used in the current iteration.
         """
         # NOTE: this should account for tempo change, weird...
@@ -531,7 +531,7 @@ def _correct_interval(self, period: Union[float, int]) -> None:
         self._last_interval = interval
         self._can_correct_interval = False
 
-    def _correct_interval_background_job(self, period: Union[float, int]) -> None:
+    def _correct_interval_background_job(self, period: float | int) -> None:
         """
         Alternative version for fixed-rate background jobs. The interval or
         period is not indexed on the clock like with the _correct_interval
@@ -545,7 +545,7 @@ def _correct_interval_background_job(self, period: Union[float, int]) -> None:
         self._last_interval = interval
         self._can_correct_interval = False
 
-    def _get_next_deadline(self, period: Union[float, int]) -> float:
+    def _get_next_deadline(self, period: float | int) -> float:
         """Returns the amount of time until the next interval.
 
         The base interval is determined by the `period` argument,
@@ -575,7 +575,7 @@ def _get_next_deadline(self, period: Union[float, int]) -> float:
         the above solution could potentially trigger non-missed iterations too early.
 
         Args:
-            period (Union[float, int]):
+            period (float | int):
                 The number of beats in the interval.
 
         Returns:
@@ -756,7 +756,7 @@ async def _call_func(self, func, args, kwargs):
 
         return await maybe_coro(func, *args, **valid_kwargs)
 
-    def _get_period(self, state: Optional[FunctionState]) -> Union[float, int]:
+    def _get_period(self, state: Optional[FunctionState]) -> float | int:
         """
         TODO: ???
 
@@ -765,7 +765,7 @@ def _get_period(self, state: Optional[FunctionState]) -> Union[float, int]:
             most recent one).
 
         Returns:
-            Union[float, int]: The period to use for the next iteration.
+            float | int: The period to use for the next iteration.
         """
         # If we don't have a state, we can't extract a period given by the user
         if state is None:
@@ -817,11 +817,11 @@ def _maybe_print_new_state(self, state: FunctionState) -> None:
                 print(f"[yellow][Saving [red]{self.name}[/red] from crash]")
                 self._has_reverted = False
 
-    async def _sleep_until(self, deadline: Union[float, int]) -> bool:
+    async def _sleep_until(self, deadline: float | int) -> bool:
         """Sleeps until the given deadline or until the runner is reloaded.
 
         Args:
-            duration (Union[float, int]): The amount of time to sleep.
+            duration (float | int): The amount of time to sleep.
 
         Returns:
             bool: True if the runner was reloaded, False otherwise.
@@ -857,7 +857,7 @@ async def _sleep_until(self, deadline: Union[float, int]) -> bool:
                 )
             )
 
-    async def _sleep_unless_jump_started(self, deadline: Union[float, int]) -> bool:
+    async def _sleep_unless_jump_started(self, deadline: float | int) -> bool:
         if self._jump_start:
             self._jump_start = False
             return False
diff --git a/sardine_core/scheduler/constants.py b/sardine_core/scheduler/constants.py
index 8403c10a..c693a75e 100644
--- a/sardine_core/scheduler/constants.py
+++ b/sardine_core/scheduler/constants.py
@@ -1,6 +1,6 @@
-from typing import Awaitable, Callable, TypeVar, Union
+from typing import Awaitable, Callable, TypeVar
 
 __all__ = ("MaybeCoroFunc", "T")
 
 T = TypeVar("T")
-MaybeCoroFunc = Callable[..., Union[T, Awaitable[T]]]
+MaybeCoroFunc = Callable[..., T | Awaitable[T]]
diff --git a/sardine_core/sequences/iterators.py b/sardine_core/sequences/iterators.py
index def6f924..dbc3e223 100644
--- a/sardine_core/sequences/iterators.py
+++ b/sardine_core/sequences/iterators.py
@@ -1,6 +1,5 @@
 from itertools import count
 from string import ascii_letters
-from typing import Union
 
 __all__ = ("Iterator",)
 
@@ -18,7 +17,7 @@ def __init__(self):
         for c in ascii_letters:
             self._iterators[c] = count(0)
 
-    def reset(self, iterator: Union[str, None] = None):
+    def reset(self, iterator: str | None = None):
         if not iterator:
             self._iterators = {}
             for c in ascii_letters:
diff --git a/sardine_core/sequences/sardine_parser/funclib.py b/sardine_core/sequences/sardine_parser/funclib.py
index 3312a344..8ab261f5 100644
--- a/sardine_core/sequences/sardine_parser/funclib.py
+++ b/sardine_core/sequences/sardine_parser/funclib.py
@@ -5,7 +5,7 @@
 from math import asin, atan, cos, pi, sin, tan
 from random import shuffle
 from time import time
-from typing import Optional, Union
+from typing import Optional
 
 from sardine_core.sequences.sequence import euclid
 
@@ -457,7 +457,7 @@ def negative_euclidian_rhythm(
     def find_voice_leading(
         self,
         collection,
-        divider: Optional[Union[list, int]] = 4,
+        divider: Optional[list | int] = 4,
     ) -> list:
         """Simple voice leading algorithm"""
         # Splitting the collection with divider
@@ -619,7 +619,7 @@ def expand(self, collection: list, factor: list, **kwargs) -> list:
         """
         factor = factor[0]
 
-        def expand_number(number: Union[int, float]) -> int | float:
+        def expand_number(number: int | float) -> int | float:
             expansions = [0, -12, 12]
             return [number + (random.choice(expansions) * factor)]
 
diff --git a/sardine_core/sequences/sardine_parser/tree_calc.py b/sardine_core/sequences/sardine_parser/tree_calc.py
index e8f60157..9deea399 100644
--- a/sardine_core/sequences/sardine_parser/tree_calc.py
+++ b/sardine_core/sequences/sardine_parser/tree_calc.py
@@ -310,8 +310,8 @@ def extend(self, left, right):
         etc..
 
         Args:
-            left (Union[list, float, int]): A token that will be extended
-            right (Union[list, float, int]): A token used as an extension rule
+            left (list | float | int): A token that will be extended
+            right (list | float | int): A token used as an extension rule
 
         Returns:
             list: A list of integers after applying the expansion rule.
diff --git a/sardine_core/sequences/variables.py b/sardine_core/sequences/variables.py
index 09bfaccf..465f60e0 100644
--- a/sardine_core/sequences/variables.py
+++ b/sardine_core/sequences/variables.py
@@ -1,6 +1,5 @@
 from itertools import count
 from string import ascii_letters
-from typing import Union
 
 __all__ = ("Variables",)
 
@@ -16,7 +15,7 @@ def __init__(self):
         for c in ascii_letters:
             self._iterators[c] = 0
 
-    def reset(self, iterator: Union[str, None] = None):
+    def reset(self, iterator: str | None = None):
         if not iterator:
             self._iterators = {}
             for c in ascii_letters:
diff --git a/sardine_core/superdirt/process.py b/sardine_core/superdirt/process.py
index 5520b338..2532c528 100644
--- a/sardine_core/superdirt/process.py
+++ b/sardine_core/superdirt/process.py
@@ -4,11 +4,10 @@
 import platform
 import shutil
 import subprocess
-import sys
 import tempfile
 from os import path, walk
 from pathlib import Path
-from typing import Optional, Union
+from typing import Optional
 
 import psutil
 from appdirs import *
@@ -49,7 +48,7 @@ def _find_vanilla_startup_file(self):
         cur_path = Path(__file__).parent.resolve()
         return "".join([str(cur_path), "/default_superdirt.scd"])
 
-    def _find_startup_file(self, user_file: Union[str, None] = None) -> Path:
+    def _find_startup_file(self, user_file: str | None = None) -> Path:
         """Find the SuperDirt startup file"""
         if not user_file:
             file_path = self._user_dir / "default_superdirt.scd"
diff --git a/sardine_core/utils/Messages.py b/sardine_core/utils/Messages.py
index bfdcb5f9..463161e9 100644
--- a/sardine_core/utils/Messages.py
+++ b/sardine_core/utils/Messages.py
@@ -2,6 +2,8 @@
 
 from rich.panel import Panel
 
+from sardine_core.io.UserConfig import Config
+
 sardine_intro = """[red]
 ░██████╗░█████╗░██████╗░██████╗░██╗███╗░░██╗███████╗
 ██╔════╝██╔══██╗██╔══██╗██╔══██╗██║████╗░██║██╔════╝
@@ -22,7 +24,7 @@ def _ticked(condition: bool):
     return "[X]" if condition else "[ ]"
 
 
-def greeter_printer(intro_logo: str, config: dict):
+def greeter_printer(intro_logo: str, config: Config):
     os.system("cls" if os.name == "nt" else "clear")
     midi_port = "Automatic" if config.midi == "Sardine" else config.midi
     config_message = (
diff --git a/sardine_core/utils/__init__.py b/sardine_core/utils/__init__.py
index 95be0d42..6e450855 100644
--- a/sardine_core/utils/__init__.py
+++ b/sardine_core/utils/__init__.py
@@ -1,6 +1,6 @@
 import functools
 import inspect
-from typing import TYPE_CHECKING, Callable, Literal, Optional, ParamSpec, TypeVar, Union
+from typing import TYPE_CHECKING, Callable, Literal, Optional, ParamSpec, TypeVar
 
 from .Messages import *
 
@@ -10,9 +10,9 @@
 P = ParamSpec("P")
 T = TypeVar("T")
 
-Number = Union[float, int]
-Quant = Optional[Union[Number, Literal["now", "beat", "bar"]]]
-Span = Optional[Union[Number, Literal["inf"]]]
+Number = float | int
+Quant = Optional[Number | Literal["now", "beat", "bar"]]
+Span = Optional[Number | Literal["inf"]]
 
 MISSING = object()
 
diff --git a/tests/fish_bowl/__init__.py b/tests/fish_bowl/__init__.py
index 199676ef..d384ef19 100644
--- a/tests/fish_bowl/__init__.py
+++ b/tests/fish_bowl/__init__.py
@@ -11,7 +11,6 @@
     Optional,
     Sequence,
     TypeVar,
-    Union,
 )
 
 import pytest_asyncio
@@ -44,7 +43,7 @@ def __init__(self, *, whitelist: Optional[Collection[str]] = None):
 
     # Analysis methods
 
-    def filter(self, events: Union[str, Collection[str]]) -> Iterator[EventLogEntry]:
+    def filter(self, events: str | Collection[str]) -> Iterator[EventLogEntry]:
         if isinstance(events, str):
             events = (events,)
 
diff --git a/tests/q b/tests/q
index 99fab6e9..db4c7604 100644
--- a/tests/q
+++ b/tests/q
@@ -1,11 +1,11 @@
 import functools
-from typing import Sequence, Union
+from typing import Sequence
 
 import pytest
 
 from sardine_core import utils
 
-Number = Union[float, int]
+Number = float | int
 
 
 @pytest.mark.parametrize(
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 99fab6e9..cd5e92bb 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -1,11 +1,11 @@
 import functools
-from typing import Sequence, Union
+from typing import Sequence
 
 import pytest
 
 from sardine_core import utils
 
-Number = Union[float, int]
+Number = float | int
 
 
 @pytest.mark.parametrize(