Musical Insturment Material : abs , pp , ps2 Realistic Tones: The system features microcomputer integrated chip, stereo speakers, soft sound effects, 2 high standard instrumental tones, 2 kinds of rhythms, 31 standard piano keys, and 2 demo methods.15 Demo Melodies: There are 15 pieces of built-in demo music available for play with DEMO demo function keys.Karaoke Singing: While playing on the piano keys or the drum keys, you can enjoy karaoke singing.8 Dance Rhythms: There are 8 built-in dance rhythms available for play with RHYTHM function key.