There was a time when perhaps the Firesign Theatre was the most constant influence in my life. I'm sure I was totally insufferable then, constantly riffing on their albums. I did get to see them some years ago at the Berkeley Community Theatre, but not sure exactly when. 15-ish years ago?
It was a golden age for countercultural comedy, generally. Besides FT there was Credibilty Gap, Congress of Wonders, Conception Corporation... and of couse the Monty Python crew put out LPs of their best bits -- not TV soundtracks but stuff prduced specifically for records, like little radio playlets.
And FM freeform radio stations actually *played* these albums (as well as LPs by George Carlin, Robert Klein and others) on the air as a regular thing!