The Harmonica Play-Along Series will help you play your favorite songs quickly and easily. Just follow the notation, listen to the online audio to hear how the harmonica should sound, and then play along using the separate backing tracks. The melody and lyrics are also included in the book in case you want to sing, or to simply help you follow along. The audio is accessed online using the unique code inside each book and can be streamed or downloaded. The audio files include PLAYBACK+, a multi-functional audio player that allows you to slow down audio without changing pitch, set loop points, change keys, and pan left or right.