Don Ellis was a hot item in 1971. He had done a few big band albums that sounded like Doc Severson plugged into Frank Zappa'a sound system, and was opening a lot of rock shows, back in the era when you could get rock and roll kids to listen to and appreciate jazz. So, Billy Friedkin makes French Connection, and gets Don to score it. Billy must have known he had a hit on his hands, and wanted a big name to put on the composer credit. Ellis does an entire, half hour score for the movie. Not a lot of this music made it into the film: evidently, Billy wanted to have a gritty film with lots of street noises, and, tastefully edited Don's score to bare bones. It works in the movie, but a lot of really good music never saw the light of day.
Over the past 20 years Australian progressive/alternative/underground rock of the early 1970s has taken on a huge cult collector following throughout the world. This is particularly so in Europe, where vast sums are paid for scarce original vinyl albums by such bands as Kahvas Jute, Galadriel, The Masters Apprentices, Fraternity, Blackfeather, Company Caine, Tamam Shud, Pirana, and New Zealand's Dragon - outfits which forged a distinctive Oz Rock sound that would eventually be embraced by an international mass audience.