The Central Australian aborigines make remarkable use of slight pitch alterations in their singing. It was this feature of their music which prompted me to make a more accurate and detailed study of the scales used in the songs I have already transcribed from T. G. H. Strehlow's collection of recordings.

The method used to determine the accurate frequency of all notes was as follows. An audio oscillator type A57321 was warmed, then plugged through a speaker alongside which another speaker reproduced the required notes from the recording. (The speed of the turntable was checked before use.) Each note of the chosen verse was taken separately and repeated until the note produced by the oscillator corresponded to it. Here some error could occur, as it was impossible to have the two notes sounding together for any length of time. It was therefore necessary to sound one and immediately follow it by the other.