a) The bone flute with three finger holes dates back to the second century A.D. and was found in excavations in in Flavia Solva. It is preserved in the Joanneum Museum in Graz.
The sonagram (example b) clearly shows the fundamental (green) and the first four overtones (orange). The curve above shows the sound wave of one channel (mono recording). The red curve on the side demonstrates the waves for the time that is marked by the eprouvettes.
Example c) represents the sound spectrum of the
wave's progress. At first, the fundamental and the four overtones can be
clearly recognized. The other highpoints only represent the sounds that
are caused by beginning to blow into the instrument. As the tone dies out,
the overtones disappear one after the other. (E. Stadler)