Jeremy Soule has been making the music for Bethesda's Elder Scrolls series since Morrowind, and his soundtrack for The Elder Scrolls V: Skyrim is very highly regarded. It features some of the last generation's best music, and is a perfect score for the huge, and still popular, RPG. However, when it comes to The Elder Scrolls VI, Soule hasn't been invited back.
On his Facebook page, the composer confirmed as much in the following statement to fans:
As so many of my fans have asked... While I’ve not said much about this out of courtesy to Bethesda, I would never turn my back on TES, and I believe that my involvement would hinge on a creative decision on their part and where they want to take the franchise. To confirm, I am currently not involved with TES VI.
Before anyone jumps to conclusions, there are a couple of things to bear in mind. As we've already mentioned, Soule has worked on the series several times before, with Skyrim's score probably being his best work, and it's important to remember that the next game is a long way off. It's possible a composer for TES VI has yet to be decided.
There was that incident a couple of years ago in which Bethesda held a Skyrim concert without Soule's knowledge, which caused a bit of a stir. Again, the game is so far off that it's impossible to make a call on this right now, but given the composer's history with the franchise and his stellar work on Skyrim, it'd be great to see him return.