Jeremy Soule took to his Facebook page shortly after the announcement of the concert, taking place at the London Palladium on November 16, to make sure that his fans knew that while his name was used in the announcement, he was not directly involved in the concert in any way. It would appear that when Bethesda hired Jeremy Soule to do the music for Skyrim, the deal allowed Soule to keep ownership of the music. Therefore Bethesda doesn't actually own any copies of it and thus will need to have the music transcribed by ear. As Soule says, while that can work to a point, there will always be some errors.