CD and book ot transcribed bass lines from our only play-along recorded with electric bass. Several choruses of 2 different blues progressions in All 12 keys. The Ultimate study in bass walking! There is also a book included of the chord charts in bass Clef, treble clef, Bb and Eb. all you friend the horn person and have them read the transposed chart and have a duet or a combo. Or..just play along with the CD which is recorded in stereo seperation which allows you to turn off the bass track and playalong with the piano and drums. Many possibilities.