Lloyd Webber, who turns 64, is one of the most successful composers of his generation, with musicals such as Cats and The Phantom of the Opera enjoying record-breaking runs on Broadway and in the West End.
As a theatre journalist, I love theatre too much to be solely a Sondheim or Lloyd Webber fan. My desert island must-have list would include titles from both of their repertoires.
In 1998 Sondheim and Lloyd Webber came together to pay tribute to producer Cameron Mackintosh, who has been responsible for producing work by both. It's a rarity to see two Broadway composers sit down and perform together, but thankfully, it's all there on tape.
So, happy birthday, Steve and Andrew, from all your fans out there in the dark. Here's to the music of the night and thanks for putting it together.