M-Tree (P.Ciaccia VLDB’1997) VA-File (R. Weber VLDB’1998) Pyramid-Tree(S.Berchtold SIGMOD’1998) hybrid-Tree(K.Chakrabarti ICDE’1999) A-Tree (Y. Sakurai VLDB’2000) IQ-Tree (S. Berchtold ICDE’2000)

由给定的谐波分量相对强度生成音符，用于乐器模拟、MIDI制作等- HARMONIC Generates a note with its harmonic wave HT=harmonic(soundname,tone,k,type) Generate a note with its harmonic wave in given tone, simulating particular type of musical instrument type=[basi