Apple’s iTunes is the most popular legal music download service. Users can download the software directly from the Itunes website, but if they do not want to deal with the limitations of using a browser-based application, they can download client software that lets them control their application.
The same software is available on the iPad and the iPhone. Apple has not yet decided to release the same type of software for the Droid. The reason is not because Droid phones are Apple‘s chief competitor, but the lack of copyright protection available on the Droid platform. Apple will release an Itunes client for the more popular droid phones eventually.

If you have a computer or a device that can use it, you can download Apple iTunes 9. The latest version of the music service’s client adds several new features, makes the task of organizing music easier. The new version also enhances the security found in previous versions of it.
You can download iTunes Agent 9 from the app store on certain Apple-made devices or you can download it from the Apple website. As long as you do not have a 56k Internet connection, you can walk away from the download for a few minutes and find the download is completed when you return

If you have never used iTunes before, you may need to take some time to familiarize yourself with how to use the software.