CAN I PLAY MUSIC OUT ON THE STREET??! LEGALLY?

Ok, so I was wondering if it is okay to take my piano out in the middle of a busy street/ work place and play music... I would not be blocking any streets, but I want to put my amps, and maybe a drummer, and we could play our music out in the open... Is that legal? Can I get a ticket or even go to jail for public disturbance? Because I see alot of hobos out on the sidewalk playing their saxophone and stuff, and no one tells them anything. (oh and our music isnt like hard metal or anything, its soft music and maybe some pop :D )