Speed up/slow down song while playing

I’d like (to buy or make) an expression pedal to speed up/slow down the tempo while playing. For example a song may start out at say 120, but then during the bridge speed up just a little to say 121 or 122, then go back to 120 for the next verse. It would be cool to program the tempo change in the song, and have it sweep during the transition, but even better would be a foot pedal to speed up or down.

I’d think this could possible via MIDI? I’m a hacker/maker, so I could program an Arduino to send MIDI messages, based on an analog pot foot pedal. Is there a list of available MIDI commands?

Or maybe add a couple options to the footswitch menu, say left to decrement BPM, and right to increment it.

Very detailed MIDI integrations (like the one you are requesting) are being discussed now, and will most likely come in one of later firmware releases. As of currently, only basic subset of MIDI protocol is supported. You can refer to manual.

You could just tap in the new tempo.

Tapping a new tempo in the middle of a song isn’t practical (for me). I think this a reasonable, real-world kind of request. A real drummer can speed up or slow down, gradually, on purpose. The BB would be that much better if it could do the same. I propose a MIDI expression pedal could be set up to vary the tempo over a settable range, e.g. toe-down = +5 BPM, toe-up = - 5 BPM. Kind of like a gas pedal for BB!

I was going to post a new request, but it seemed to fall under this category. I was going to ask for tempo at the song part granularity rather than song. Default for all parts could be initial tempo (if one didn’t care about changing tempos) but one could change later parts and save them. Many players speed up naturally by a notch or 2 by the end of the song and this is a good thing as it builds energy. And as someone mentioned, tapping out the tempo isn’t always practical.

As far as I know myself, this very feature is being actively discussed and will probably be added very soon. (Like really soon-ish)