Nonharmonic natural modes give struck percussion instruments their clangy identity
Evidence
Percussion instruments are characterized acoustically by the modes of vibration they are able to support and the position of the strike point with respect to the node and antinode points of each mode (e.g., see the discussion on plucked and struck strings earlier in this chapter). Percussion instruments can be considered in three classes: those that make use of bars (e.g., xylophone, glockenspiel, celeste, triangle), membranes (e.g., drums) or plates (e.g., cymbals). In each case, the natural mode frequencies are not harmonically related, with the exception of longitudinal modes excited in a bar that is stimulated by stroking with a cloth or glove coated with rosin, whose mode frequencies are given by Equation 1.35 if the bar is free to move (unfixed) at both ends and equation 1.36 if it is supported at one end and free at the other. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1268 (
#expands, via linked claim)
Categorization
- corroborated: 3 independent passages support this claim
- XREF: connects to: Marimba-like instruments with joined bars and resonators arose independently on three continents; A hammer strike excites every mode an instrument can support simultaneously — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1266; Where you strike a percussion instrument governs which modes sound (+7 more)
Broader Connections
- Percussion instruments divide into bar, membrane, and plate classes
#expands(0.85) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1268 - Instrument stiffness versus tension determines how widely its modes are spaced
#expands(0.78)