I've visited Amsterdam a few times... great city, and not just for the red light. Get out and see as much as you can outside of that one mile magnet (although that can be fun too). There are a couple of great music stores that I recall - one just south of the city core... I believe it's on Vijzelstraat and another within the core with some great vintage gear - not far from the train station IIRC.
Last time I was there I stayed at a hotel in Rembrandt Square just south of the core which is a pretty vibrant little area on it's own - as is the area that encompasses the hard rock cafe to the south west of the core.
Heed way to the cyclists, and have fun!