Activist duo Pat Humphries and Sandy O are Emma's Revolution. The two songwriters follow the footsteps of American folk music icon Pete Seeger and will present music for peace and justice at 7:30 p.m. Saturday, May 30, at the Ashland Community Center, 59 Winburn Way, Ashland. Tickets cost $18 in advance, $20 at the door and are available at Paddington Station and Music Coop in Ashland. The Rogue Valley Peace Choir and Peace House will sponsor the concert. Call 482-8915 for information.