The Doctor writes his piece in Gallifreyan. (TV: Music of the Spheres)
Ode to the Universe was a short, discordant piece of classical music composed by the Tenth Doctor.
Inspired by the "Music of the Spheres", the natural sound of the universe as heard through the TARDIS' harmonic filters, the piece received its debut at the 2008 Proms at Royal Albert Hall when, due to a rift in time and space, the Doctor was briefly able to communicate with a proms concert in progress.
The Doctor conducted the performance of the piece, which sounded like an orchestra tuning their instruments. He was pleased with the results. A Graske aboard the TARDIS at the time used the distraction caused by the piece to slip through the portal and briefly cause havoc with the audience. (TV: Music of the Spheres)
Behind the scenes[]
Although it's been hinted that the Doctor has played a role in the composition of other, more famous songs, this is one of the few occasions in which he claimed direct credit for composing a piece of music.