Percussion Instruments
Membranes or solids that can vibrate
very wide range: drums, cymbals, bells, gongs, xylophones, triangles….
lack of a well-defined harmonic structure (resonate at a variety of frequencies, the higher frequency are not whole-number multiples of the lower one!)
each instrument behave in a different way
complex 2D or 3D structure of nodal and antinodal lines