咩係 non pitched percussion instruments

Percussion instruments that do not produce a definite pitch are generally termed unpitched percussion(non pitched percussion instruments ).These include most drums (snare drum, bass drum, drum set, etc.) and also other instruments used mostly for special effects. Some of these instruments which add colour to an ensemble are the triangle, gong, castanets, rattle, cowbell, woodblock, tambourine, maracas, claves, and whistles.
non pitched percussion instruments 是不可調較及不可奏出不同高/低音的敲擊樂,如大、小鼓drums,搖鼓tambourine、三角triangles、沙搥maracas、揺鈴sleigh bells、木棒woodblocks等等.
Some percussion instruments can play melodies. These are called tuned percussion. The xylophone, glockenspiel, marimba, vibraphone,and timpani are all tuned percussion instruments.
pitched percussion instruments 是可調較及可奏出不同高/低音的敲撃樂,如定音鼓timpani、鋼琴piano、鋼片琴glockenspiel、鐘琴celesta等等,所以,有D pitched percussion instruments 可奏出不同的旋律。

2008-01-10 14:12:23 補充：
Other unpitched instruments also are heard in the orchestra. These include the Chinese gong(中國的大鑼), a large metal disc whose deep and sonorous clang lends grand emphasis to a musical climax.

non pitched percussion instruments = 不可轉音的樂器 (自作的~~~)

非被投的打擊樂器

非被紮牢的敲打器具

非被紮牢的敲打器具