In about 1981 Michael Murphey started calling himself Michael Martin Murphey. As a general rule of thumb:
Without Martin = good
With Martin = a bit boring
Best of all were the early 1970s when he was hanging out in Austin with Willie, Jerry Jeff, the Lost Gonzos and the rest of the gang. His first two albums - "Geronimo's Cadillac" and "Cosmic Cowboy Souvenir" - date from the period and are a couple of crackers. Both were reissued a few years ago on Raven Records with added live tracks and are worth tracking down.
Here are a couple from 1972's "Geronimo's Cadillac" album: "Waking Up" and "Calico Silver".
Here is a clip of him in the Martin years performing an old favourite from pre-Martin days, "Texas Morning":