The Bleepin' Button Whisperer

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 basically play the app for you like some kinda robot roadie. This screen sets up a single trigger. Your changes save as you make them, so just tap Done when you're finally finished messin' around.

Which options show up depends on what bleepin' controller you're mappin', but every trigger starts with these two absolute must-haves:

MIDI Event

A MIDI Event is the incoming message that fires the trigger — a note, a control change (CC), & so on. Tap to choose the message & its channel; the row shows your choice, like "CC 4 on Channel 1." (Riveting stuff, we know.)

Action

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

Response Curve

The Response Curve shapes how the controller's travel maps to the action. In other words, it's where the magic pretends to happen.

• Linear — the controller & the parameter move together, 1:1. Boring but dependable, like your ex.
• Logarithmic — most of the travel works at the quiet end; great for a natural volume feel. Your ears will totes thank you.
• Exponential — most of the travel is subtle, & the top of the range pushes hard. ZOMG drama at the end.
• S-Curve — stable at the extremes & fast through the middle; good for crossfades. Basically the Goldilocks of curves.

Minimum & Maximum Value

These clamp the input event's useful range within 0–127. Anything outside the range gets ignored, so you can dial in exactly the sweep you want without all the garbage. The minimum always stays below the maximum (shocking, we know).

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 & pick your poison:

• Momentary — active once a value greater than 0 is received. Press & hold, it's on. Release it, it's off. Done.
• 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 a separate press & release message & you want the action to respond to both. (Sounds complicated? It kinda is.)
• Toggle — treats the action as an on/off state. Crossin' the threshold on the way up sends the "On" action while droppin' back below sends the "Off" action. Use this for anything with a held state like a mute, a hold, a light. Your drummer's gonna love this.

Threshold

This is the value at or above which the controller counts as on. Values below it get ignored. It defaults to 1 for Momentary & 64 for Toggle. (Don't ask why. Seriously.)

Inverted

This setting reverses the input value direction. 0 becomes 127 & vice versa. Super handy when a pedal is mounted or wired backwards, which, let's be real, happens to literally everyone.

Active

This turns the trigger on or off. Switch it off to suspend the trigger without deletin' the binding, so you can bring it back later when you inevitably change your mind.