I Believe In Father Christmas, performed by Greg Lake (from the group Emerson, Lake, & Palmer), was released in 1975, launching his solo career. 

The song was very popular in the UK, reaching #2 on its Singles Chart (Queen’s Bohemian Rhapsody was #1).

The original music video of Lake performing the tune is here: 

Greg Lake – I Believe in Father Christmas

Marking the song’s 50th Anniversary, there is a newly released animated music video posted here:

50th Anniversity Video – I Believe in Father Christmas

I was reminded of this song last year by BillyG, long-time Fiddlerman Forum member, who provided a link to a 2021 performance of the tune by UK’s Sarah Brightman in a holiday special filmed at Christ Church Spitalfields in London (thanks, BillyG) – video is here: 

Sarah Brightman: I Believe in Father Christmas