Here is a listing of summer outdoor concert series in Fairfax county.
Wednesday night concerts, 8 pm, Fairfax City Hall, http://novasummerconcerts.wordpress.com/fairfax/summer-concert-series-city-of-fairfax/
Thursday night, Take a Break concerts, 7 to 9, Lake Anne Plaza, Reston, http://lakeanneplaza.com/wp-content/uploads/downloads/2010/06/LakeAnne_Summer_Series.pdf
Thursday night, 7 pm, Falls Church Concerts in the Park, Cherry Hill Park, http://www.fallschurchva.gov/Content/Government/Departments/CommunityServices/RecsParks/CITP2010.aspx?cnlid=3382
Friday Night Live! summer concerts, 6:30 to 10:30, Herndon Rocks!, http://www.herndonrocks.com/schedule.php
Friday night concerts, 7:30, Lake Accotink Park,Springfield, http://www.fairfaxcounty.gov/braddock/pdfs/bn_flyer.pdf
Friday night concerts, 7:30, Royal Lake Park,Fairfax, http://www.fairfaxcounty.gov/braddock/pdfs/bn_flyer.pdf
Saturday night summer concerts, 6 – 8:30, Fairfax Corner, http://www.fairfaxcorner.com/images/pdf/summerconcerts_2010.pdf
Saturday night summer concerts, 7:30 to 10, Reston Town Center Pavilion. http://restontowncenter.com/iframe/documents/2010ScheduleRestonConcertsontheTownFINAL.pdf
Sunday night concerts, 6 to 8, Great Falls Village Centre. http://www.gfvcca.com/concertFlyer2010.pdf
Summer Entertainment Series, various Fairfax county parks: http://www.fairfaxcounty.gov/parks/performances/
City of Alexandria summer concerts, various dates and venues: http://alexandriava.gov/Concerts
City of Fairfax Band, various dates: http://www.fairfaxband.org/calendar/index.php
Fairfax Symphony Orchestra, various dates at various parks, http://www.fairfaxsymphony.org/
Thanks for the info! There is a lot of stuff going on in Fairfax. For some more info check out the Fairfax county website too. Hope this helps.