The Billy Joel song that begins with “It's nine o'clock on a Saturday” is “Piano Man.” The lyric opens its famous scene in a piano bar, where the narrator observes the regular customers and the performer entertaining them.
Joel released “Piano Man” as the title track of his second studio album in 1973. The song drew on his experience playing piano in a Los Angeles lounge, where he worked under the name Bill Martin before his recording career took off. Its characters combine observation, loneliness, and hopes for escape.
The song became Joel's signature recording and gave him the nickname “Piano Man.” Its harmonica-led arrangement and waltz-like feel helped distinguish it from many conventional pop-rock hits of the period.
Listeners sometimes confuse the song with “New York State of Mind,” another reflective Joel standard, or with “Just the Way You Are,” one of his major ballads. Neither begins with the Saturday-night piano-bar scene described in the opening line.