subsequence.link_clock

Ableton Link clock adapter for Subsequence.

Wraps aalink.Link and adapts its asyncio-native API to Subsequence’s 24 PPQN pulse model. Requires the optional link extra:

pip install subsequence[link]

Usage:

link_clock = LinkClock(bpm=120, quantum=4.0, loop=asyncio.get_running_loop())
beat_origin = await link_clock.wait_for_bar()
# ... in the pulse loop:
await link_clock.sync(beat_origin + pulse_count / PPQN)

Module Contents

class subsequence.link_clock.LinkClock(bpm: float, quantum: float, loop: asyncio.AbstractEventLoop)

Thin wrapper around aalink.Link for Subsequence’s pulse-based clock.

Parameters:

• bpm – Initial tempo in BPM (proposed to the Link session).

• quantum – Beat cycle length — 4.0 means one bar in 4/4 time.

• loop – The running asyncio event loop (required by aalink).

Join the Link session immediately, proposing bpm and setting the bar length to quantum beats.

disable() → None

Disconnect from the Link session.

request_tempo(bpm: float) → None

Propose a new tempo to the Link session.

Other peers may accept or reject the change depending on their own session rules. Subsequence’s sequencer will pick up the network- authoritative tempo on the next pulse.

async sync(beat: float) → float

Wait until the Link session beat reaches beat, then return beat.

This is the primary timing primitive used by the sequencer loop. Calling await link_clock.sync(beat_origin + pulse / PPQN) for each successive pulse gives accurate, Link-synchronised timing.

async wait_for_bar() → float

Wait for the next quantum boundary (bar start) and return it.

Use this to start the sequencer at a musically clean position that is phase-aligned with all other Link participants.

Returns the beat value at which playback should begin (beat_origin).

property beat: float

Current absolute beat position in the Link session timeline.

property num_peers: int

Number of connected Link peers (not counting self).

property playing: bool

Whether the Link session transport is playing.

property quantum: float

Beat cycle length (e.g. 4.0 for one bar in 4/4).

property tempo: float

Current session tempo in BPM (authoritative from the Link network).