What I know is this song came out in the early 70's I believe and the singer has a lot of reverb on his voice and the song's fade out has him singing "Get it on". It's definitely not T-Rex's Bang A Gong. The singer has a voice very suited for R'n'R. Any ideas?

My first instinct was "Long Cool Woman In A Black Dress" by the Hollies.

Fantastic! You are correct.

Nice call, especially since he's saying "had it all", not "get it on".