I did a quick search through the excluded product list and I didn't see Amazon MP3s on there. You'd just have to sign up, get approved and then change the links to your Amazon code, an easy process.
You'll be getting 4% (which increases with volume) on every song (most which are $1) so 4cents per sale. Cashout is $10 for US as either gift card or direct deposit. You're going to need a lot of traffic and sales to reach that.
You could also look into the iTunes affiliate programs which give a flat 5%.