🎵 KEEPIN' TIME (or else)

Zomg All Da Toys » Beat Sync

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 we hope you are.)

One Tempo, One Clock (For Real This Time)

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 get set when nobody else is messin' with 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. Fancy, amirite?
• MIDI Clock can now hear the difference between each beat & downbeat & use that to update the tempo. It's got ears, apparently.
• Backing Tracks get processed when played through the AuxDock to figure out their beat grid & change tempo as needed throughout the track. We're basically your roadie now.

Followin' The Beat (Or Else)

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 falls in line like obedient little soldiers. If you're actively gettin' 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 follows. It's called democracy.

Metronome

This is the most obvious integration of the beat clock includin' the count-in. Y'know, the clickety-clack thing that makes you wish you'd practiced more.

AuxDock Atmosphere

This plays a canvas of sound that can be started, stopped & changed with those changes synchronized to the current beat. Fancy ambient stuff. You're welcome.

AuxDock Pedalboard

What if your guitar effects could stay in sync with every aspect of the song? Plot twist: they can. 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 gets played at the right time. Even if your finger-dragging is terrible, we got your back.

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 caffeine-addled maniac.

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 with your sweaty palms.

The clock only runs when somethin' is listenin'. Nothin' is bein' kept in time, nothin' is tickin'. It's basically a lazy clock.

Dynamic Tempo & Meter (For When You Can't Make Up Your Mind)

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

• {tempo: 72} changes the tempo to the new BPM value. Revolutionary, we know.
• {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. We're not monsters.
• {ramp: 4} glides from the current tempo to new tempo over a number of measures, beats, or seconds rather than immediately. Typin' just a number specifies the number beats. Usin' 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. Math is fun.

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 code.

Enablin' Beat Sync

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 cruisin' at.

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 sharin' the tempo with other devices or that it's been disarmed, confirmin' that beat sync is off. Riveting stuff.

Where It Counts

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 gets scheduled ahead of time so it lands exactly where it should. It's called plannin' ahead. Revolutionary concept, apparently.

Why It Doesn't Drift (The Nerdy Bit)

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 like a drunk uncle at karaoke.

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 wins again.

Beat-synced audio gets 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 gets 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 like it actually knows what it's doin'.

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 legitimate settin' & looks identical from across the stage. Oops.