What is the theme song for on BBC?

The BBC does not have one single theme song. It's a huge organization with many different channels and programs.

* BBC One has a well-known theme, a fanfare composed by Ronnie Hazlehurst in 1956. It's a classic and recognizable tune.

* BBC Two has a different theme, written by David Arnold in 1991. It's more contemporary and has a distinctive electronic sound.

Other BBC channels and programs have their own theme tunes, so it's impossible to say there's just one "BBC theme song."