A very nice PLAY-A-LONG book by JAMEY AEBERSOLD JAZZ publishing house, is destined to all intermediate and advanced musicians playing any musical instrument. This book includes tones for all tunes (C, Bb, Eb and musical instruments in bass key). The attached CD includes great "life" accompaniment without a melodic instrument or singing, that are waiting just for you. For practising the piano and bass, right and left channel are divided as followed: R-piano, vibes, guitar, drums and L-bass, drums). Very precious and useful product.