If music soothes the savage beast, there's no telling what it'll do for us ordinary Joes. To find out, drop by some of these weekend concerts.

* For sounds under the stars, take the family to the free military band concerts running every weekend throughout the summer. At the Sylvan Theater on the grounds of the Washington Monument, the Air Force Band will be performing Fridays and the Marine Band Sundays, through August. On the West Terrace of the Capitol the Army Band will be playing every Friday through August. All concerts begin at 8 p.m. 426-6700.

* The St. Paul Chamber Orchestra launches the Kennedy Center's chamber music summer festival this weekend. On Friday at 8:30 in the Concert Hall, you can tune in to a couple of Bach concertos and a Haydn symphony, featuring soloist Young Uck Kim. On Saturday at 8:30 three of Bach's Brandenburg concertos are scheduled. Tickets are $11. After the concert, take a walk on the Kennedy Center Terrace where you can pick up drinks and snacks and listen to live music. The KenCen folks are encouraging casual attire for these warm evenings, so leave your tie on the rack. 254-3776.

* The Capital City Jazz Festival stokes up the Convention Center Friday and Saturday. Miles Davis and the Dirty Dozen Brass Band will play at 8 p.m. Friday; M'Boom Re: Percussion Ensemble (with Max Roach) and the World Saxaphone Quartet will play Saturday at 2 p.m.; Philly Joe Jones & Dameronia, and the Howard University Jazz Repertory Orchestra will close the festival Saturday at 8 p.m. Admission is $15 per concert. (Reviews of some of the performers' records appear on page 15.)

* And don't forget the free music in town this weekend courtesy of "Riverfest." (A rundown on all those doings begins on page 5.) Sunday's "Tribute to Muddy Waters" with the Rhythm Masters, Jimmy Rogers and the Legendary Blues Band looks particularly good. It starts at 6 p.m. at Stage I at Ninth and Water streets SW.