Summer music in Sea Cliff is now in full swing this week with outdoor concerts being held on both Thursday and Friday nights.  On Thursday, the Roger Street Friedman Band will perform at Memorial Park from 7 to 9 pm in a Sunset Serenade concert sponsored by the Civic Association, and on Friday from 7 to 10 pm, Jenn Gerrity and PBJ&L will open for Tiberius to kick off this season's Sea Cliff Beach Friday Night Music Series.   This past Thursday, the Lazy Dogs (above) performed at Sunset Serenade.