The history of blues harmonica is, to a surprising extent, a history of busking: playing outdoors, for tips, on the sidewalks or in the street.
Most of the great African American players worked the streets: Little Walter, Big Walter, Sonny Terry, both Sonny Boy Williamsons, Junior Wells, Will Shade, Sugar Blue, Peg Leg Sam, Charlie Sayles: they all spent some portion of their lives busking for spare change on Maxwell Street, Beale Street, Bleecker Street. (Bessie Smith busked as a girl on 9th Street in Chattanooga, Tennessee.) My own teacher, Nat Riddles, was a master of the streets; "El Cafe Street" was the name of his show. I worked the streets of Harlem and Times Square with Sterling "Mr. Satan" Magee for five amazing years. Busking changed my life. It could change yours.
Busking the streets is nothing like performing on an indoor stage. There's no club owner or set times, no built-in crowd. No roof over your head. There's no gig. There's just you, your music, and the crowd that you might stop--if you're good enough. If you're looking for "edge," as in existential risk, busking is right up your alley.
A busker always has his (or her) eye on three things: 1) the weather; 2) the cops; 3) the amount of foot traffic passing by his pitch. (A pitch is the location where you've chosen to take your stand.)
Rain can kill your busking day, unless you're playing in a covered location. The cops can shut you down for many reasons, but two predominate: 1) You're too loud, leading somebody in the neighborhood to complain; and 2) You've drawn such a big crowd that you're creating an impediment to the free flow of pedestrian traffic, or, worse, leading pedestrians to walk in the street and endanger themselves.
Foot traffic is crucial. It isn't hard to find a busking pitch so far from the beaten track--in an abandoned industrial part of town, for example--that the cops will leave you alone. But you won't make any money, because there's no foot traffic. By the same token, if you set up on Columbus Circle in Manhattan, where I played a few times many years ago, you'll have all kinds of foot traffic. But you'll be shut down almost immediately, because the spot is patrolled by officers in green uniforms whose job it is to say "No!" to buskers.
You need to find the sweet spot.
This page offers some useful links for buskers and prospective buskers, along with inspirational videos. While you're at it, don't forget to check out my two books about the busking life: Busker's Holiday, a novel, and Mister Satan's Apprentice, a memoir.
THREADS ABOUT BUSKING on the Modern Blues Harmonica forum: