YAMAHA Synthesizer DX21 PLAY BOOK cassette tape. Tape Contents: Side A: Introduction ~ Basic Operation ~ Performance Memory Side B: Performance Memory ~ Tone Data ① ~ Tone Data ② ~ Edit ~ Tone Data ③ *Please note that playback has only been confirmed for approximately 30 seconds at three points on both sides (beginning, middle, and near the end of the tape). As this is an old item, please refer to the photos and understand before purchasing.