Getting your music into the iTunes Music Store can be a huge step to gaining necessary exposure, especially if you are a band that is unrepresented by a major music label. Publishing your music on iTunes does not cost anything, but will require you to complete a specific process in order to do so. You can publish music on iTunes as often or as infrequently as you'd like.
Fill out an iTunes Music Store application. This is required for all artists wishing to put music into the iTunes Music Store. It is a way for Apple to review the content of your music and make sure that it fits the image they have established. You can find the iTunes Store Application at https://phobos.apple.com/WebObjects/MZLabel.woa/wa/apply.
Wait for Apple to review your application. Depending on the frequency at which they receive applications, this can take a few days or a few weeks. They will contact you at the e-mail address you've provided in the application with your approval.
Upload your music to the website Apple specifies in your application approval e-mail. This will upload your music directly to the iTunes Store, and allow you to choose cover art, provide a description and set a cost. Once the upload is complete, it can be accessed from the iTunes Store by anyone with iTunes installed on their computer or any owner of an iPhone or iPod Touch.
Paste this URL in your browser to access the iTunes Music Store Application: https://phobos.apple.com/WebObjects/MZLabel.woa/wa/apply