Kirby was concerned about the demise of traditional cultural practices of African people. Whilst at Wits, he was encouraged by his colleagues, people like Raymond Dart and Louis Maingard, to make a comprehensive study of the musical practices of the indigenous peoples of southern Africa. Between 1923 and 1933, supported by several study grants, he travelled thousands of miles, undertook more than nine special expeditions as well as many shorter excursions in his ancient Model T Ford to places like Pietersburg and Potgietersrus, to the area then known as Sekhukhuneland, Transvaal, and to Swaziland and Botswana. He was hosted by local chiefs and taught to play the instruments he encountered. He managed to purchase many of them, and this collection is now known as the Kirby Collection and is housed at the South African College of Music, University of Cape Town.

The book Musical Instruments of the Native Races of South Africa, first published in 1934, was the culmination of these research trips. It has become the standard reference on indigenous South African musical instruments, but has been out of print for many years. This third edition, with a revised title, contains an introduction by Mike Nixon, Head of the Ethnomusicology and African Music programme at the South African College of Music, and new reproductions of the valuable historic photographs by Paff and others, but leaves Kirby’s original text unchanged.