But it's rare moments like the odd big tipper – and the amazing coincidence in the video below – that make it all worthwhile.
Witness a street musician in Berlin singing "Smalltown Boy," a 1984 song from Bronski Beat that was a big hit in Germany. About 30 seconds in, a man walking a dog strolls up to him and begins singing along. The pair finish the song, and the man says, "It's a hit!" He should know, because as it turns out, he happens to be the guy who wrote it, Jimmy Somerville.
"Is it you?" The stunned busker asks. "It's me," he confirms, and the busker's awestruck "Oh my God" says it all.
Now check out the original song, which is predictably earning all sorts of new fans thanks to this video's viral success.