Morning of the Earth is a 1971 classic surf film by Alby Falzon and David Elfick.
Tamam Shud were recording tracks for the surf film Morning of the Earth including their song First Things First. Their main lead singer, Lindsay Bjerre was having voice problems so they recorded the song using lead guitarist Tim Gaze music producer G. Wayne Thomas was unhappy with Gazes vocals and asked Broderick Smith Carson to fill in. According to Bjerre, Tamam Shud were not informed and only found out about the switch at the films premiere according to Smith, he had Tamam Shuds knowledge and permission.
Source: Wikipedia