Billy Joel released "Piano Man" in 1973 as his first single. Interesting, the song never made it to number one in the charts, having gotten to # 25 at its highest popularity in 1974. The song's opening stanza is:

It's nine o'clock on a Saturday

The regular crowd shuffles in

There's an old man sitting next to me

Makin' love to his tonic and gin

Billy Joel wrote the song from real life experiences in a piano bar from the Executive Room bar in the Wilshire district of Los Angeles, where he played from 1972-73. He had a contract dispute with a New York recording company and could not play under his real name, so he chose the stage name "Bill Martin" (His full name is William Martin Joel).

Each stanza is credited to real life characters he observed while in the Executive Room. "The waitress is practicing politics" refers to Joel's first wife Elizabeth Weber, who actually worked there while Billy Joel played the piano.

Even though it never reached number one (highest it reached in the US Billboard was 25), Rolling Stone ranked it 421 of the best 500 songs ever in 2004. It was selected by the Library of Congress National Recording Registry to be preserved forever in 2016.

More Info: en.wikipedia.org