Via an email tip received over the weekend, it has come to light that composer Michael Giacchino is preparing to score another Pixar project, according to an interview with Swiss blog, Owley.
After confirming his work on Pixar director Brad Bird's live-action film Tomorrowland, and mentioning another mystery project, he simply mentions work on an upcoming Pixar project and leaves it at that.
Oh, and a Pixar film — but I don't dare say any more on that either. [translation from German]
There are certainly a number of upcoming Pixar projects this could reference. Randy Newman has likely already finished his score on Monsters University. Thomas Newman recently confirmed he'll be working on next year's The Good Dinosaur. Given that Pete Docter had a successful run with Giacchino on UP, I would put my money on his upcoming project, Inside Out.
Giacchino has worked on a number of popular Pixar films: The Incredibles, Ratatouille, UP, Cars 2 and shorts: La Luna, Day & Night, Dug's Special Mission, and Partly Cloudy. He is also well known for his work on the last two Mission Impossible films, the new Star Trek series, and the popular TV series: LOST and Alias.