I say sorta OT, because while the topic isn't directly related to Halo, it can indirectly be related to how future music with companies like 343 could be done. It appears Marty has started his own company, as of April 2014, "Marty O'Donnell Music"

With this business, he could, in theory, be contracted from 343 in the future, for even just a song or two in future Halos. 343 doesn't have to worry about in-house hiring him, as he can now be contracted. I'm assuming.

While I'm very happy that 343 is bringing fresh music to the table from new faces, I would be giddy if there were a few surprises from one of the individuals who helped bring Halo's iconic music to surface.