A horde of picnickers, sunbathers, bicyclists, joggers, moms, dads, dogs, cats, kids and yes, music lovers, descended on the Foundry yesterday for the opening of the Concerts on the Canal. Frisbees, tennis balls and champagne corks flew through the air, and more than one bottle of beer bit the dust in the hot summer sun.

The series, going into its fourth season, will be presenting concerts on alternate Sundays through Sept. 21. A wide variety of musical forms will be featured, from blues and jazz to folk, gospel and bluegrass. Admission is free.

The headliner at yesterday's show was jazz guitarist Charlie Byrd. His music -- a bluesy blend of pop and South American styles -- was perfect complement to the setting. Bright melodies and brisk rhythms had the crowd swaying to the songs, and Byrd's airy instrumental feel added to the lightheartedness of the event.

Celtic Thunder opened the show with a sprightly collection of traditional Irish jigs and reels. The five-piece group had people dancing on the cobblestone pathways, and several listeners added their own accompaniment by tapping on beer cans and coolers.

The Foundry certainly doesn't have perfect outdoor acoustics, and the jets flying into National Airport provide a symphony of their own. But on a sunny day, with music wafting over the canal, none of that seems to matter.