Before I went on holiday, I began to think about getting my Rock Band guitar controller to act as a MIDI instrument in GarageBand. I’m still fiddling with it, and since implementing a couple of extra features, I’m increasingly happy with the results.
The setup in ControllerMate, initially quite straightforward, is gradually becoming fairly hairy. Here’s what it looks like now. Click through to see a bigger, annotated version.
- Sends MIDI notes based on the fret you are holding while strumming up or down. Release the fret to stop the note, exactly as you’d expect in Rock Band or Guitar Hero.
- Pick a major key by holding a fret button and tapping ‘Start’. First fret (green button) + start = C major, second fret = D, etc.
- Hold ‘Back’ while picking a key to make it minor. e.g. 3rd fret + ‘Back’ + ‘Start’ = E minor. Update: in the most recent version, you just hold a fret and hit ‘back’ (rather than ‘back’ + ‘start’ together)
- Additionally hold the next fret up to make it sharp. e.g. 1st + 2nd fret + ‘Start’ = C# major. 2nd + 3rd fret = ‘Back’ + ‘Start’ = D# minor.
- Within the chosen key, first fret (green button) is the root note, while the others are intervals on the major/minor pentatonic scale. e.g. for C major, the frets are C, D, E, G, A. For C minor they are C, Eb, F, G, Bb.
- Move the pickup selector to the 2nd position to engage ‘drone’ mode, in which the root note for the current key is played on a second MIDI channel whenever it is played. Handy for having a different MIDI voice sustaining the chord. I’d like to add ‘chord’ and ‘strum’ and ‘arpeggiate’ modes in other pickup switch positions, though I think strumming and arpeggiating could be better handled by plugins responding to simpler MIDI notes which represent the current chord.
- The whammy bar controls the MIDI pitch bend. Different VST plugins choose to respond to pitch bend in different ways, so depending on your instrument you can even set this up to be a guitar slide rather than a simple bend.
- Left and right on the D pad to move up and down by 7 semitones. allowing you to explore the circle of fifths. Sort of. This bit needs some more work.
- Upper set of frets play up an octave.
If you’ve got a Rock Band guitar and want to use it as MIDI instrument, in GarageBand or anything else, I’m very happy to make the current version of my patch available. Most of the features should work with the Guitar Hero controller too, though I have not tried this yet. Let me know if you want to try my setup and don’t fancy re-creating it from the picture above, though obviously you’ll need the MIDI-enabled beta of ControllerMate, which is available to paying ControllerMate users who have paired their registration details with their forum membership, on the beta forum.
I think ControllerMate is easily worth the $15, and access to the MIDI-aware beta should make it an even easier decision.
Background / further reading:
- Wikipedia: major and minor and the circle of fifths.
- Jazz Primer: Pentatonic scales.
- I just found the Slapyak Guitar Hero Midi Controller, which uses an Arduino and is much better than my effort.
- Phil Gyford recently pointed me at this really interesting design for a geometric keyboard, which I think I might have something to learn from.