Doing the Riven of a Thousand Voices encounter in the intended way, specifically the part where you need to destroy 6 of Riven's eyes simultaneously does play her phase two battle theme as intended, BUT, after dropping down during the damage phase (when you get back to your respective hall) the soundtrack switches back to the phase 1 theme. Not a lot of people complained about it, we are a few really, but we love doing this encounter the intended way and I personally love the soundtrack in this game, it's such a shame it doesn't play correctly during the encounter Hope it's not too nitpicky, otherwise great work out there Bungie!