Just to let you guys know, that's not the actual "Ethan Mars' Main Theme". That's actually a piece called "Mars" by Nick Ingman and Terry Devine-King, which was used in one of the trailers for Heavy Rain.
In fact, "Mars" is loosely based on "Lux Aeterna" from Requiem for a Dream. Therefore, I am pretty confident that you'll never hear that piece performed at VGL.
This is the actual "Ethan Mars' Main Theme," in case you were wondering.