Mason Williams said that he wrote this song as "fuel," or a standby, for the classical guitar in case anyone wanted to hear him play something for them, therefore he called it "Classical Gasoline." During recording, "Gasoline" was inadvertently abbreviated to "Gas" by the music copyist, giving it the name "Classical Gas."
This song appeared as a video on the Smothers Brothers' television show, for which Williams was a writer. The song was played behind a video which consisted of nothing more than photographs of great works of classical art flashed at near cinematic speed on the screen. You saw each picture just long enough to recognize it but nowhere nearly long enough to remember the name. The fact that the paintings were classics originated the name. This is one of the first music videos ever produced.
Mike Post, who had made a name for himself producing the First Edition and their hit "Just Dropped In (To See What Condition My Condition Was In)," produced the album. Speaking with the Archive of American Television, he explained, "Mason played me this one little song in A minor called 'Classical Gas.' And it really was good. He said, 'I just want to do bass, drums, guitar and piano.' I said, 'We need an orchestra for some of the vocal songs on the album, we can do a big, aggressive instrumental thing.'"
Post wrote a middle section for the song because it needed a bridge, and conducted the orchestra. The song became a huge hit and got Post into television - he became the musical director on The Andy Williams Show in 1969 and went on to write many famous TV theme songs, including The Rockford Files, Hill Street Blues and The Greatest American Hero.
Mike Post got some static from a Smothers Brother after recording the orchestra for this song. Said Post: "I came in after the session was over, and Tommy Smothers turns to me and says, 'That's the most over-arranged piece of s--t I've ever heard.' At that time I was 22 and not going to take anything from anyone. I was very sure of myself to cover up the fact that I was scared to death. So I told him to get out. To his credit, he came back the next day and said, 'I was completely wrong, it's a great record.'"
Listen for the Wagnerian tuben horns on this track. A relatively rare instrument, it's kind of a cross between a French horn and a trumpet. It's also known as a Wagner tuba.
This song won Grammy awards in 1969 for Best Instrumental Composition, Best Contemporary Pop Performance, Instrumental, and Best Instrumental Arrangement. The arrangement award went to Mike Post, and it was very special for him, since he was the first session musician to make the transition to production and win a Grammy.