Street musicians

In some way they are the truest artists. Let's find interesting people performing out in the open.
I'll start with this:
visiting frisco for work, just walking around the downtown area by the mall, came across 4 acapella singers, all old cats, been doing it for decades, standing there belting out old motown favorites...few of us stayed for 30min listening. just amazing what they were doing...
Tracy Chapman began as a busker. Her earliest music is some of her most compelling.

Related: I'd highly recommend the film, Once. It has a great soundtrack as well.
The Persuasions?? A little of this stuff goes a long way.
But I like 'A Cappella Dreams' Great for a change of pace and to check out how your system does with the human voice.