I am rather partial to a pedal about the place. I love most things about getting out on my bike: the fresh air, the endorphins, the sights, the sounds. But I am often a little saddened by the loss of musical potential. I spend a good chunk of my professional life trying to transfer energy from spinning wheels / motors to musical devices and yet when I venture out on my bike I just let that potential silently pass. Not entirely silently of course, there is the sound of the rubber on the road and various squeaks and rattles (and occasional panting) but why aren't they part of a wider ensemble?
I have even made a number of pedal-powered musical contraptions over the years. Why have I never made one that just attaches to my bike? Maybe I am worried about mixing work and leisure. Unlikely, given how much fun I derive from both.
I also have a love-hate relationship with dinging my bell when I am riding on a shared path. I've thought about attaching a cat collar bell so there's a more constant, friendly sound. Maybe a bike-powered mechanical musical instrument is the answer here too...