Whether you're a karaoke singer or an auditioning professional, the Pro Vocal series is for you. The books contain the lyrics, melody and chord symbols for eight hit songs. The CDs contain demos for listening, and separate backing tracks so you can sing along. The CD is playable on any CD player, but it is also enhanced so that PC and Mac computer users can adjust the recording to any pitch without changing the tempo! This innovative feature allows singers to transpose songs to any key to suit their voice type. Perfect, for home rehearsal, parties, auditions, corporate events, and gigs without a backup band.