Galt MacDermot never really intended to be a theatre composer - the few Broadway scores he wrote are only a small fraction of his lifetime musical output. He was always more of a jazz guy and a session musician - he only did "Hair" because of a connection through a manager, and got asked to do other shows because of how successful "Hair" was. He never initiated projects - he only worked on things that other people brought to him.
That said, I happen to love the score to "Dude". It's poorly recorded, but a lot of the songs are kind of great. And "Human Comedy" has gotten a lot more respect as time has gone by.
But Galt has had his greatest success in the world of hip-hop, where he's revered as something of a pioneer. Tons of his old jazz records have been used for samples and beats, and he's even won Grammys for songs by Run D.M.C. and Busta Rhymes.
The money he made off of "Hair" has meant he's been able to do whatever he wanted in music all of his life - if you're really curious, check out his website and see just a bit of the vast amount of music the man has written beyond the theatre.
Yes, I'm a fan.
Galt MacDermot.com