Austin City Limits Music Festival
A local tradition after just four years, this fall fest features three days of roots rock and countrified rhythms on eight outdoor stages. The acts reflect the kind of fare (Ben Harper, Los Lobos) presented on the PBS series of the same name.

Summerfest
The World's Largest Music Festival, as it says right there in the Guinness Book of World Records, the Big Gig takes over a picturesque 75 acres of festival grounds on Milwaukee's scenic lakefront. The 11-day blowout spotlights everyone from pop stars to polka maestros - whoever's touring tries to route through Milwaukee in July.

Bumbershoot
Seattle, Washington
A four-day bounty of pop, rock, country, Latino, hip-hop, reggae, roots, classical, ethnic, and opera make for a sublime goodbye to summer each Labor Day weekend. The weather's great, the setting (Puget Sound with Mount Rainier in the background) is gorgeous, and the entertainment is top-shelf (2004 headliners included Nas, Liz Phair, and Bo Diddley).

Chicago Blues Festival
In June, this Grant Park legend pulls upwards of 750,000 fans downtown to witness the biggest annual reunion of Chicago's storied blues players (as well as blues talent from outside of Chicago).

Smithsonian Folklife Festival
Washington, D.C.
This two-week extravaganza on the National Mall each June and July celebrates contemporary American musical traditions and the foreign influences that flavor them.

3. great not-so-big festivals
Telluride Bluegrass Festival
Telluride, Colorado
This boutique June festival high in the Rockies limits ticket sales to 10,000 a day, lending intimacy to the gathering while broadening the initial bluegrass theme to absorb jazz, Celtic, pop, folk, world, and other musical styles.

Leavenworth International Accordion Celebration