Mix 104.1 and Emerald Lounge had a busy Saturday. At noon, the radio station and the Revere Hotel restaurant hosted a Mix Lounge show featuring “American Idol” winner Phillip Phillips, who played for local fans — including Needham’s Olympic gold medal gymnast, Aly Raisman. At 6, the station and Emerald hosted a second Mix Lounge performance, this time featuring the Berklee College of Music-trained duo Karmin, with Amy Heidemann and Nick Noonan.