Harmonix has let slip that Rock Band 3 will feature vocal harmonies at their PAX East panel. The developers rolled out their vocal harmony tech in The Beatles: Rock Band last autumn, which proceeded to receive strong critical acclaim. Nothing else about Rock Band 3 has been unveiled so far apart from Harmonix boldly claiming it will revolutionise the genre. Expect a big E3 showing during one of the console-holder’s events and at EA’s show, as the game is due out the end of this year.