Blow air through the holes of a spinning disk to produce different tones. More holes and a faster-spinning disc make for higher-pitched sounds.  Demonstrate musical intervals, the relation of pitch to frequency, and autocorrelation in psycho-acoustics

This 'Siren Disc' consists of a metal disc about 180mmD, mounted on a central shaft so that it can be rotated. The disc has 4 rows of holes around it and when a fine jet of air is blown through the rotating holes, a 'siren tone' is produced. The holes are 24, 30, 36 and 48 and this is a ratio of 4, 5, 6, and 8. The combined sound of all 4 holes creating a siren sound is a natural musical chord. For the blow tube only, see 3770001.

Instructions included.  Made in Australia.