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Beat Sync: The Vibe Police That Keeps You From Being a Hot Mess

Everything in music demands a synchronized beat... the metronome click, a drum groove, a delay slap, tremolo pulse, an arpeggio, etc. OnSong accounts for this through a shared beat clock that is constantly in-the-know about tempo, time signature, and when each measure starts. Beat Sync is what starts & synchronizes multiple components in OnSong so you're always in the pocket. (Or at least trying to be.)

One Tempo, One Clock (No Excuses)

There's a single clock for the whole app. It knows three things: the tempo, the time signature, & where you are in the bar — which beat, & which subdivision of that beat. The tempo of the beat clock is usually set by the underlying song bein' played, but it can be driven by other internal & external factors. These include:

• Song Tempo is the most common way the tempo & time signature gets decided when literally nothin' else is hollerin' at it.
• Ableton Link lets you connect OnSong to other apps or equipment so OnSong can stay in beat & phase with Ableton, a metronome app, or a wrist worn watch. Basically, friendship bracelets for your gear.
• MIDI Clock can now hear the difference between each beat & downbeat & use that to update the tempo. It's got ears, y'all.
• Backing Tracks are processed when played through the AuxDock to determine their beat grid, changin' tempo as needed throughout the track. We basically steal the rhythm right outta the audio file.

Following The Beat (Because Driftin' is Embarrassing)

Everything in the OnSong^® app now subscribes to the beat clock. The first component to use the beat clock can set the down beat. For instance, if you start the metronome, the downbeat is heard right away & everything else synchronizes with the metronome. If you are actively received beat & phase information through somethin' like Ableton Link or MIDI Clock, the metronome will start on the next beat, but align downbeats to the beat clock. First in wins & everything else falls in line like it's supposed to.

Metronome

This is the most obvious integration of the beat clock includin' the count-in. Click clack. You're welcome.

AuxDock Atmosphere

This plays a canvas of sound that can be started, stopped & changed with those changes synchronized to the current beat. Ambience that doesn't betray you.

AuxDock Pedalboard

What if your guitar effects could actually stay in sync with every aspect of the song instead of wanderin' off like a lost puppy? The AuxDock features timed pedals that can have time parameters set to a musical subdivision. Quarter, dotted eighth, & so on, followin' tempo changes as they happen on: - Delay - Tremolo - Phaser - Wah

AuxDock Chordboard

This lets anyone play chords in the song. It uses an arpeggiator & strum system. Beat sync ensures each chord change & note is played at the right time. Even you can do it.

AuxDock Drum Rack

Is a full drum machine that ensures the groove, fills, & ending land where you'd expect rather than where you tapped like some kinda wild animal.

AuxDock Virtual Instrument

This is a guitar that can strum or pick to the chords in your song. Beat sync lets it all play in time rather than whenever you touch it like a toddler at a keyboard.

The clock only runs when something is listenin'. Nothin' is bein' kept in time, nothin' is tickin', nothin' is burnin' CPU for no reason.

Dynamic Tempo & Meter (Because One Speed is For Quitters)

A song doesn't have to hold one tempo anymore. Each sections can carry its own directives & the beat clock is updated when each section is selected:

• {tempo: 72} changes the tempo to the new BPM value. Boom. Done.
• {time: 6/8} changes the time signature meter to 6/8. The new meter starts on a clean downbeat rather than part-way through a bar like some kinda amateur hour.
• {ramp: 4} glides from the current tempo to new tempo over a number of measures, beats, or seconds rather than immediately. Typing just a number specifies the number beats. Using a syntax like 1,2 would change it over a measure & two beats. Appendin' an "s" to the end like 2s would define the number of seconds independent of the tempo. Smooth AF.

These are live changes, not edits! They move the tempo of everything without rewritin' the song's own tempo. It's like magic, except it's math.

Enabling Beat Sync (aka: The On Button)

Beat Sync appears wherever it's relevant, as a small pulsin' LED with the current BPM beside it. The LED blinks on the beat, so you can see at a glance both that sync is on & what tempo it's on. No guessing games here, friend.

Tappin' it toggles that surface's sync. When you do, a chip floats briefly in the dock — armed, it offers Ableton Link… as the way of sharing the tempo with other devices or that it's been disarmed, confirming that beat sync is off. Nice & simple.

Where It Counts (aka: The Intro That Doesn't Suck)

When the metronome counts you in, beat-synced instruments stay silent through the count & start on the first real downbeat. They don't play along with the count & they don't come in late — the first beat is scheduled ahead of time so it lands exactly. No surprises. No awkward lag. Just tight.

Why It Doesn't Drift (aka: The Science Behind Not Bein' a Disaster)

Two details do most of the work, & they're worth knowin' because they explain why beat-synced audio in the OnSong^® app stays tight where other approaches wander off like they're lost.

The clock's grid is anchored to the device's monotonic hardware clock, not to a repeatin' timer. A timer accumulates a little error on every tick; an anchored grid computes when each beat should happen, so beat ten thousand is as accurate as beat one. Math > guesswork.

Beat-synced audio is scheduled ahead of time rather than played when the tick arrives. The clock can say precisely when an upcoming beat will occur, so a drum hit is handed to the audio engine in advance with that timestamp attached. If the app is busy for a moment, the audio has already been scheduled & still lands on the beat. Boom.

If somethin' sounds like it's driftin', check whether its Sync is actually on — an effect with Sync off is runnin' on its own rate knob, which is a legit setting & looks identical from across the stage. Don't blame us for your oopsies.