Here are four shortcuts that will help you speed up the way you write MIDI in REAPER.
I like to have as much control as I can over MIDI just using my mouse and very minimal keyboard shortcuts. So these shortcuts play a big role into being super efficient with my MIDI mouse writing.
Paint a line of notes
Hold Ctrl + Alt (Windows) or ⌘ + ⌥ (macOS) as you left drag click to paint a line of notes.
The space between these notes will match whatever you have your grid setup to. That means if your grid is setup to 1/16, it will write 1/16 notes consecutively.
This is perfect for quickly writing kick drums or hihats.
Hold Alt (Windows) or ⌥ (macOS) as you left drag click to erase notes.
This is the eraser tool which is super handy for quickly go back and forth between writing and deleting. Just hold the modifier key to quickly switch to an eraser!
Hold Alt (Windows) or ⌥ (macOS) and left click and drag the edge of a note to stretch MIDI notes.
This is one of my favorites MIDI shortcuts! Being able to grab a group of notes and stretch them to whatever length I want is so handy.
This is perfect for situations where maybe you want to half-time your chord progression. Or slow down your melody a bit. It also gives you a lot of room to play with some interesting timings!
Adjust Note Velocity
Hold Alt (Windows) or ⌥ (macOS) and left click drag the note center up and down to adjust their velocity.
This is one of the fastest way to adjust MIDI velocity!