“Santa Claus Is Coming to Town” was written by James “Haven” Gillepsie and was first performed in the US on American singer Eddie Cantor’s radio show in 1934. Gillepsie was a vaudevillian who became a songwriter. Fallen on hard time he got a call to write a Christmas song for Cantor just after he found out his brother had passed away.
Being grief-stricken Gillepsie at first declined the offer. Then while on the subway he remembered his childhood with his brother and how their mother would warn them that Santa was watching to see how they behaved. He then changed his mind and wrote the lyrics to the song in fifteen minutes, He asked John Coots to compose the music and this Chritsmas song became a hit in just 24 hours of its debut.