Thank you for the music

BART station, Berkeley, 5.20pm, Tuesday
A middle-aged busker sits on an instrument case, an accordion draped across his lap, a black beret atop his head. He is waiting for . . . Shattuck Avenue to shape-shift into the Champs d'Elysses, perhaps? Minutes later, as if on cue, he springs to action, foot tapping, head listing from side to side, arms madly pumping away on the accordion. The tune: Money, Money, Money by ABBA.
BART station, downtown San Francisco, 8.28am, Wednesday
A paunchy punk with a cherry red mohawk strums a classical guitar and channels Johnny Cash: And it burns, burns, burns, the ring of fire, the ring of fire.