The Clicky-Clicky Magic Box

A MIDI trigger connects an incoming MIDI message — from a foot controller, expression pedal, or control surface — to an action in OnSong, so your hardware can drive the app hands-free. (Yep, your feet do the work now. You're welcome.) This screen sets up a single trigger. Your changes save automatically 'cause we're not monsters, so just tap Done when you're finally finished messin' around.

Which options pop up depends on what kinda controller you're hookin' up, but every trigger starts with these two absolute must-haves:

MIDI Event

A MIDI Event is the incoming message that kicks off the trigger — a note, a control change (CC), whatever. Tap to pick the message & its channel; the row shows what you picked, like "CC 4 on Channel 1." (Riveting stuff, we know.)

Action

The Action is what OnSong actually does when the trigger fires. Tap to browse the action chooser; the row shows your action, or "Unassigned" (oops). For a variable control change like an expression pedal or knob that sends a smooth 0–127 sweep, you'll also peep:

Response Curve

The Response Curve shapes how your controller's travel translates to the action. In other words, we're lettin' you cheat.

• Linear — controller & parameter move together, 1:1. Boring but honest.
• Logarithmic — most of the travel happens at the quiet end; feels natural for volume 'cause your ears are weird that way.
• Exponential — most of the travel is chill, then BAM the top of the range goes bonkers.
• S-Curve — locked down at the extremes, zippy through the middle; chef's kiss for crossfades.

Minimum & Maximum Value

These lock down the input event's useful range between 0–127. Anything outside gets ignored, so you can dial in exactly the sweep you want. The minimum always stays below the maximum (math, y'all).

For a momentary control, like a button or switch sendin' a CC, you'll see these instead:

Behavior

Behavior decides how presses map to the action. Tap the row to cycle through:

• Momentary — active once a value greater than 0 shows up. (Duh.)
• Latch — fires the action on both edges, but with no on/off value. Press fires it once, release fires it again, each just a plain action. Use it when your controller sends separate press & release messages & you want the action to respond to both.
• Toggle — treats the action as an on/off state. Crossin' the threshold on the way up sends the "On" action; droppin' back below sends the "Off" action. Perfect for anything with a held state like mute, hold, or a light.

Threshold

This is the value at or above which the controller counts as on. Values below it? Ignored. Defaults to 1 for Momentary & 64 for Toggle.

Inverted

This flips the input value direction. 0 becomes 127 & vice versa. Lifesaver when a pedal is mounted or wired backwards. (We've all been there.)

Active

This turns the trigger on or off. Flip it off to pause the trigger without deletin' the binding, so you can dust it off later.