Things had gone more or less according to plan at the HFS-tival Saturday until Courtney Love showed up. The routinely bratty singer, a surprise addition to the show, strutted onstage at RFK Stadium with her guitar, played two songs, then dived into the crowd. She emerged a minute later, her dress shredded, and unleashed a burst of expletives at the audience, challenging one member, "Come up here -- I'll kick your butt!" And then she was gone, hustled offstage by a few beefy security types.

In a daylong show like the HFS-tival, you can count on moments like that. This year's incarnation of WHFS-FM's annual alternative-rock gathering served up plenty of them -- such as the incongruous appearance of the other surprise guest, Tony Bennett -- along with lots of sun, sweat and beer.

The music started at noon on the main stage with a solid but largely unappreciated performance by D.C.'s Shudder to Think, which played before a mostly empty stadium. Juliana Hatfield's apparently underrehearsed band labored under a sound mix that caused bass and guitar to congeal into a sonic sludge that rendered "Universal Heart-Beat" almost unrecognizable.

Well-received sets by Better Than Ezra (highlight: a what's-wrong-with-this-picture medley of Prince's "When Doves Cry" and "I Would Die 4 U" in the middle of the group's hit "Good") and longtime left-of-the-dial favorite Mike Watt followed. English newcomers Bush next turned in a batch of extended, improvisation-heavy versions of the band's songs that sometimes wandered too far, as with "Everything Zen."

English ska veterans General Public had the misfortune to come onstage only minutes before some dense, lead-gray clouds blew in and opened up, but the band overcame the elements with the show's best stage presence, led by frenetic vocalist Ranking Roger. Even the foul weather eventually played along: During "Rainy Days," the sun finally shot through the clouds.

Love's antics came next. They were a jolt of unexpected nonsense almost required in a show this widely promoted and this heavily dominated by the regulars of WHFS's playlists. (Only the fest's second stage, off in RFK's parking lot, featured genuinely unsung acts like Archers of Loaf.)

But few acts anywhere at the concert were as bizarre as Primus, which came onstage after Love. The insistent grooves of the band's eccentric hits, like "My Name Is Mud," reduced the front quarter of the field into a surging mass of heads and arms and flying bodies.

After a second bout of rain and lightning that caused most of the field's population to retreat into the stands, Polly Jean Harvey's emotive, full-throated singing brought out the layers of pain, longing and lust in songs such as "Come On Billy," an intensity not matched by her band.

Soul Asylum produced a set packed with numbers from its 1993 hit album, "Grave Dancers Union," and its new release, "Let Your Dim Light Shine." At times, singer Dave Pirner waxed sarcastic -- he whipped out a trumpet to play the riff from Paul McCartney's "Silly Love Songs" at the end of "Misery." But the band sounded serious to the point of obsession on the feedback-drenched "Crawl," when Pirner and guitarist Dan Murphy looked ready to smack their guitars into the amps.

During Tony Bennett's brief interlude of gentility and style that followed Soul Asylum, it was remarkable to see the denizens of the mosh pit cease body-surfing to clap calmly along to "Old Devil Moon."

The Ramones, who closed the show, are rumored to be packing it in after this year, but they showed no signs of slowing down Saturday. They barely paused between their breakneck renditions of such classics as "I Wanna Be Sedated" and "Rockaway Beach." As a song from their newest release, "Adios Amigos," put it, "I Don't Want to Grow Up."