The purpose of certain things is a mystery to science. Male nipples. Drum solos. The cycle lane at the north end of Blackfriars Bridge.
The third may well never be explained. And before you all write in, we know that the first is a consequence of the way embryos develop as 'default female'.
The standard explanation for percussion solos is that drummers, having so much kit, are the ones with the van. So the rest of the group have to suffer them, because they need the lift home.
However, this is clearly not the case with the drum-kit cyclist Puncturekit, alias busker David Osborne (above). His drum kit is his transport. He's adapted his road bike so it unfolds into a drum kit with five cymbals, three snare drums and a foot pedal. After his gigs, he reassembles it as a bike and rides home.
We first saw him in action a couple of years ago in a Hackney park. Things have moved on since, as the Evening Standard's article on him last year reported.
And on Saturday David was at work in Oxford St (right), exploiting the canyon acoustics of its side streets.
Now, if only Brompton could get going on this idea... I'm sure its designer and slide-rule meister Andrew Ritchie could devise cyclable vibraphones, pedalled tubular bells, bicycle marimbas. Being an itinerant orchestral percussionist would be so much easier.