Amazon.com: Song clips are available for all titles in the MP3 Music Downloads Store and on all MP3 albums product pages. To listen to song clips, either go to an MP3 album product webpage or search for a song within the MP3 Music Downloads Store. Click the "Preview All" button above the track list to hear all samples. To listen to a single clip, click the arrow to the left of track. (Note: If you don't see the "Preview All" button, you won't be able to play any clips. In that case, you may see a message with instructions to download the Flash Player.)
CDUniverse: CDUniverse song clips are available in both RealAudio and Windows Media formats. For help playing CDUniverse song clips, scroll down to the bottom of any webpage and click on the "Help Section" link.
To listen to song clips, you need the appropriate streaming audio file media players, all of which are freely available on the Internet. If you don't already have them, the easiest way to get the players you need is to click on the "help pages" links on any CD product page and follow the online merchant's instructions.