So my friend sent me this and he said there are 74 bands represented in this picture, but I have a hard time locating more than 3..

http://img.photobucket.com/albums/v470/trihouse/bands.jpg

Guns N' Roses are easy, U2 is graffitti on the right hand side on the building and I'm assuming the queen with the two pink guns is Sex Pistols. Can you come up with any more?