This video, via LOOK MUM NO COMPUTER, demonstrates the Synth Bike 2.0.
It’s a synthesizer on a bike. What more do you want?
Its a 1973 raleigh chopper with a drum machine/sampler/analog synth built into it in the front panel and top of the frame.
Tempo can be controlled by a built in clock tempo, or the front wheel, so the faster or slower you go the faster or slower the music goes.
If any readers have made their own synth bike, leave a comment with the details.