B1: Fundamental and first overtone of a constant tone. A background played by strings. In the first figure below we show a spectrogram of a clip from the start of the Firebird Suite passage. The horizontal bars for the constant string background are more evident.
In the second figure, we have processed the recorded sound so that only the fundamental and overtones of a single constant pitch are evident. Here the string background is clearly audible throughout, although a few horn notes are at the same pitch (no doubt an intentional effect by the composer).
