The song played during the Garnett commercial is O Fortuna from Carmina Burana...I believe they also use part of this for the intro. When the players come in they switch to Ayo Technology, or at least part of it. BUT I think the thing you're thinking of is the Theme (Lux Aeterna) from Requiem for a Dream. Specifically, they use the commercial adaptation that was in The Two Towers trailers a few years ago. You can YouTube it. This song ends when KG roars. Then they switch to Ayo Tech.