Have yourself a merry little Christmas, if the fates allow

The best Christmas songs are the sad ones: "Fairytale Of New York", "It's A Big Country", "Blue Christmas" and "Have Yourself A Merry Little Christmas", which is probably the best actual Christmas song of all.

The lyrics were written by Hugh Martin and the music by Ralph Blane. It was unveiled in the 1944 film "Meet Me In St Louis". Judy Garland sings it to comfort her young sister, who's upset at the news that the family are moving to New York.

The lyric has changed through the years. The film's director thought it was too sad and persuaded Martin to change "it may be your last" to "let your heart be light". When Sinatra came to record a version on an album called "A Jolly Christmas" he asked him to change it again. This time "until then we'll have to muddle through somehow" became "hang a shining star upon the highest bough". Sinatra's got form when it comes to making clunky changes to lyrics - see his altering of Jesus to "Jilly" in his version of "Mrs Robinson".

In later life Martin, who was a Seventh Day Adventist, re-wrote his song as "Have Yourself A Blessed Little Christmas" and performed it as "we will all be together, if the Lord allows", a form of words he claimed were in the original but were swapped for "if the fates allow" to make the song less religious.

Last night I caught Larry Lamb and the cast of "Gavin And Stacey" doing it at the end of a repeated Christmas special. I think "if the fates allow" is actually the best line in the whole song. As we re-group for Christmas and think about who's here, who's not and what's changed, that's the line that strokes the heart strings. Have yourself a merry little Christmas.