There is a whole stretch of shops in Ochanomizu that is definitely musicians' heaven!
These shops sell all sorts of musical intruments and related items, scores etc etc. If you are crazy about music, you'll go bonkers in this area.
What to buy: Check out their electric guitars that are hung outside many of the shop fronts. You'll be awed by the variety and the colours!
Unlike most Tower Records, this one has 80% japanese music so i found it a great place to buy local music. The price is decent too.
What to buy: music !
What to pay: average