We have been using a system called Blast-It! MP3 from a company called Corporate Systems. You can select any mp3 music you have on cd and then store it on a harddrive to play with no moving parts as stated above. Our system hooks up via RCA jacks. We have had 0 downtime on the hold music since replacing the old system with this. The website for this system is
http://www.corpsys.com/ They may not list it on the site, but if you call, they still have them.