This little gem (6"x4.5") is PERFECT for any and ALL rhythm section players. It has chord progressions only (no melodies) for over 400 standard-type songs, written with large chord symbols that are easy to read in dim lit clubs, and has a large spiral binding that allows easy, flat opening on your music stand. If you play piano , bass or guitar, you MUST get this book. This is NOT some book that "might" help you - this is a proven and handy tool that is used by all kinds of musicians (like US!) on every single jazz gig they play.