I was working on another Mac-related project looking up background on a 1988 episode - one of the ones with Bruce McGill in the cast.
I put together a table comparing Rick's work from 1973 to 2007 (end of SG-1) to Bruce's. Each actor brings different experience to the table, and it adds to the episodes.
I am sharing it because Bruce has been in a LOT of movies, and he's such a chameleon as a character actor that you may not have recognized him. He's also done voice work for video games and narrated other things (this list stops at 2007, so it doesn't include his work in Family Guy, The Cleveland Show, and American Dad!).
Also, for another example of Bruce singing, check out the Miami Vice episode Out Where the Buses Don't Run - he sings "I Fought the Law and the Law Won" - watch Don Johnson in the front seat. This was also the episode that led to him being cast in MacGyver.
Enjoy...Link to Table