Forum Moderators: skibum
* Make friends with bloggers that are related to music. (Comment on their posts and that sort of thing.) Then ask them if they would like to sell your product.
* Hang out on affiliate related discussion forums. Ask questions and offer answers when you can. Pay very careful to their guidelines.
* If appropriate, maybe some music schools or teachers would like to put the affiliate links on their sites to make some extra cash.
It's all about networking.