With the rise of talented egomaniacs like Kanye West and Lil Wayne, rap groups have been in dreadfully short supply. Yet, Philly's Roots Picnic is lucky to have three of the best crews ever in one place this year: menacing siblings Clipse; ubiquitous hometown heroes the Roots, of course; and the three most visible of the Wu-Tang alumni: Method Man, Raekwon, and the wondrous Ghostface Killah.

But even the Picnic's non-rap selections this year are unusually rhythmic. The dexterous, rubbery Vampire Weekend headlines this picnic after scoring a No. 1 album, Contra, the way spiritual forebears Talking Heads never did. The Very Best, whose Afropop/Western pop fusion has sampled the film True Romance and M.I.A., among others, will come to life. And let's not forget one-line wonders Das Racist, who will no doubt have all of Penn's Landing shouting, "I'm at the Pizza Hut/I'm at the Taco Bell/I'm at the Combination Pizza Hut and Taco Bell."

But whatever you do, do not miss the astounding, paint-faced, one-woman show known as tUnE-yArDs (also known as Merrill Garbus), who loops junkshop percussion a la Beck, strums a ukulele, and wails like Nina Simone.

- Dan Weiss

The third annual Roots Picnic with Vampire Weekend, Method Man, Ghostface and Raekwon, Clipse, Mayer Hawthorne, The Very Best, DJ Jazzy Jeff, tUnE-yArDs, Bajah and the Dry Eye Crew, Das Racist and Pattern Is Movement at 2 p.m. Saturday at Festival Pier, Penn's Landing, Columbus Boulevard and Spring Garden Street. Tickets: $66-$80. Phone: 877-598-8497, www.livenation.com.

Non-Commvention

The Non-Commvention is a music industry gathering of noncommercial radio stations that's been hosted annually by WXPN-FM (88.5) at World Cafe Live since 2008. That's the boring part.

The exciting part is that because all those DJs and programmers are in town, lots of acts come through to perform, and there's a pay-one-price ticket deal to get in, even if you're not an insider.

This year's impressive itinerary, which kicked off Thursday night, piggybacks on some marquee act performances at other (less intimate) venues this weekend. John Legend & the Roots will play Non-Comm on Friday night, for example, and The National will be at WCL at noon Saturday. But there's plenty of other intriguing action exclusive to the event. Retro soul man Eli "Paperboy" Reed is on at noon Friday. Rising New Orleans star Trombone Shorty headlines the downstairs stage on Friday night, and Cyndi Lauper (who's been reborn as a blues woman, if you can believe that) and Ike Reilly are on tap upstairs.

- Dan DeLuca

Non-Commvention with Trombone Shorty, John Legend & the Roots, Cyndi Lauper, and others beginning at noon Friday at World Cafe Live, 3025 Walnut St. Tickets: $75, or $100 for two. Phone: 215-222-1400. See www.xpn.org/concerts-events/non-comm-2010 for full schedule and ticket info.