I am morally certain he was on a couple episodes of Alice as well.
Unfortunately, his IMDB entry doesn’t agree with your morality. 
Does anyone remember David Bowie from Labyrinth? Did you know he was a songwriter and singer?
That Jones guy? Was he as famous as that guy who played Father Brian Peter George St. John le Baptiste de la Salle Eno in the last episode of Father Ted?
His Wikipedia sez he was on Flo, the Alice spinoff, which is close enough, I’d like to think. Hmm. Wonder why the discrepancy between one and the other.
IMDB does note that he sang the theme song for Flo (see the “Music Department” heading), and the Wikipedia entry for Flo mentions this, as well.
I would tend to trust IMDB more than Wiki, due to the latter’s reputation for inaccuracies added by users, though IMDB probably suffers from the same sort of thing. However, when we’re talking about a couple of 35-year-old TV series, either (or both) may be inaccurate.
BABY OIL!!! AAAAAA NOOOOO!!!
(Damn no caps coding!)