Many parks in various metro areas offer free musical concerts one or two days a week through out the summer. Some even offer free movies once the sun goes down. I know of several in Oregon, but please check your own state and metro area for programs near you.
City Parks and Recreation Websites
Portland Parks and Recreation Summer Free For All
Tualatin Hills Park & RecCity of Hillsboro Parks & RecreationLake Oswego Parks & RecreationWoodburn Rec & Parks, Out and AboutSalem Recreation Guide
Flicks on the Bricks 2010
Pioneer Courthouse Square-Downtown Portland. Movies begin at dusk.
July 23rd: Ferris Bueller’s Day Off
July 30th: Three Amigos
August 6th: Sixteen Candles
August 13th: The Muppets Take Manhattan
August 20th: Jaws
Movies in the ParkPortland area, mainly Multnomah County
Portland Parks and Recreation
Movies in the Park, runs Friday June 25th – Friday, September 10th at parks and other outdoor settings around Portland. Pre-movie entertainment begins at 6:30pm and movies will begin at dark. Some movies will be subtitled for those with hearing disabilities, please see web site for schedule.
Flick by the FountainBeaverton City Park at 5th and Hall
Beaverton Flick by the Fountain, every Friday in August in Beaverton City Park (across the street from the Beaverton City Library). Pre-movie entertainment will begin at 8:00pm and the movie will play at dusk.
Movies on the CommonsCentral Downtown Tualatin
Tualatin Movies on the Commons begins on Saturday, July 3rd with family-friendly movies starting at dusk. Movies every Saturday night until August 14th at Tualatin Commons.
Pictures in the ParkMain Street Park in Gresham
Gresham Pictures In The Park dates are Friday, August 6th, 13th, 20th and 27th. Music will start at about 7:00pm and the movies around dusk. There will be free refreshments.
Movies in the Park
Wilsonville Movies in the Park on Friday July 16th and July 23rd; and on Friday August 13th and 27th. Lawn opens at 8:15pm and movie will play at dusk.
West Linn Movies in the Park at Mary S. Young Park runs every Saturday night in August. Movies begin at dusk.
Vancouver Movies at Esther Short Park on Friday July 2nd, 9th and 16th. Movies begin at dusk.
Vancouver Movies at Haagen Park on Friday July 23rd and 30th, movies begin at dusk.