Join SUMM at The City of Mercer Island’s Mercerdale Park for the summer outdoor concert series, "Mostly Music in the Park." August 21’s schedule features Prom Date Mixtape, a 80s new wave band.

Bring a blanket, a few low-back chairs, a picnic dinner and your family for an evening of music and entertainment. Food trucks will be on-site each week, as well as hands-on arts and crafts for kids of all ages!