[For a split second he's about to say he can teach both at the same time, but... maybe going from two jobs to four right away would seem a little strange.]
Literature, then. [He can do both equally well, but at least teaching literature eliminates the risk of having to listen to a bunch of tone-deaf people attempting to make music.] Thank you very much for having me, Your Highness. It's an honour to be able to work alongside you.
[Can't say "be co-workers" because that'd make it sound like they're equal, goodness.]