I've been meaning to buy this 2006 Soul Jazz compilation for a while and only just got round to doing so, collating some of disco producer Tom Moulton's - originator of the 12" single, amongst other things - best mixes.
Developing longer mixes mainly as a way to keep people dancing to a song longer than the standard 3 minute singles would allow (although to me it improves them for pure listening - virtually all my favourite Disco tracks are 5 minutes plus), many of the mixes on the compilation are promo-only or unreleased versions from his remix ouvre of around 4000 (!!) tracks (according to this interview with the man). With so much material to choose from, hopefully Part 2 will be on the way soon.
Choosing a sample track was a challenge due to the quality of the compilation, but I love the extended instrumental section (a Moulton trademark) in Dreamworld:
Don Downing - Dreamworld (Tom Moulton Mix)(MP3) : Alt Link
You can buy A Tom Moulton Mix and hear more audio samples at Soul Jazz and Amazon.