Category: Resultant Tones
Published on Friday, 15 January 2010 17:36
Written by Bruce Gale
ccasionally, resultant tones or "ghost notes" can confuse an unwary section or band director. Resultant tones are faint notes resulting from the sounding of two loud notes simultaneously. There are two types. The first, which is lower in pitch, corresponds to the difference in vibration between the original two sounds. The other resultant tone - higher than the original two sounds - corresponds to the sum of their vibrations. You can demonstrate the effect for yourself by asking two advanced flute players to assist you. with each flute tuned to A=440hz, ask one to play C a twelfth above (1056 hz) and the other to play the E flat above that (1267.2 hz) and tune them perfectly. Then ask both players to play simultaneously. When this is done, the A flat two octaves and a third below will also be heard. This latter note is a resultant tone or "ghost note". It is best to use flutes for this experiment since they produce the purest sounds, thereby maximising the possibility of success.