The 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 do the heavy liftin' while you keep your hands where they belong (on your instrument, not your phone). This screen sets up a single trigger. Your changes save as you make 'em, so just tap Done when you're finally finished messin' around.

Which options show up depends on what kinda 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), whatever. Tap to pick the message & its channel; the row shows your choice, like "CC 4 on Channel 1." (We know, riveting stuff.)

Action

The Action is what OnSong does when the trigger fires. Tap to pick from the action chooser; the row shows the assigned action, or "Unassigned" (whoops). 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 the controller's travel maps to the action. (Translation: we're makin' it feel less janky.)

• Linear — the controller & the parameter move together, 1:1. Boring but honest.
• Logarithmic — most of the travel works at the quiet end; great for a natural volume feel. Your ears will thank you.
• Exponential — most of the travel is subtle, & the top of the range pushes hard. For when you like drama.
• S-Curve — stable at the extremes & fast through the middle; good for crossfades. Chef's kiss.

Minimum & Maximum Value

These clamp the input event's useful range within 0–127. Anything outside the range gets ghosted, so you can dial in exactly the sweep you want. The minimum always stays below the maximum. (Math! Wow!)

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 is received. Press & release? 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. (Fancy!)
• 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. The classics.

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. (We did the math for you. You're welcome.)

Inverted

This setting reverses the input value direction. 0 becomes 127 & vice versa. Handy when a pedal is mounted or wired backwards. (Hey, it happens. We don't judge.)

Active

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