Few instruments do a good job as the only rhythm instrument in a dance band; in my 2014 sample I only saw guitar and fiddle. I can't play guitar for dancing anymore because of my wrists, and the piano has to give up a lot in exchange for its large range. A goal I've had for a long time is to figure out how to get the same full sound from something built around a mandolin.

As a rhythm instrument, the way I play it, the mandolin has a percussive bite and drive that's hard to get with the piano. This drive contributes a lot to the dancing, and is something I really enjoy about a mandolin-piano rhythm section. Take away the piano, though, and everything is high frequency.

I've played with a bunch of ideas here for augmenting my mandolin playing:

• DIY organ pedals.

• Build a computer vision system that maps from hand shape and position to chord, and then choose bass notes from the chord. Trigger the bass notes with foot pedals.

• Make a hat with a tilt sensor, and use head angle to choose bass notes. Foot pedals as before.

• Use vocals, perhaps processed, to fill out the sound.

• Whistle into a microphone, which controls a bass synthesizer, so I can whistle bass lines.

Recently I tried a new combination:

• Whistle into a microphone to select bass notes, trigger the bass notes with foot pedals.

Here's a video:

(youtube)

I'm running my standalone pitch detector which translates the whistling into MIDI, with pitch bend to send fractional pitch. I tell my MIDI router what key and mode I'm in, and it listens for I, IV, V, and either vi (minor) or VII (mixo) by picking the nearest option. I have this driving both a bass that's triggered by the foot pedals, and an atmospheric droney pad that just runs. I have the pad set to only change notes on a pedal tap, however.

It's not as flexible as the bass whistle, because I need to choose in advance what key and mode to play in and it only does four bass notes, but it also is much less likely to make weird awkward noises when I screw up slightly.