On Saturday, about 50,000 music faithful will pour into Merriweather Post Pavilion for this year's Virgin Mobile FreeFest, featuring 20 acts, three stages and one giant ferris wheel.

This year's bill is packed with more up-and-comers and buzz bands than ever. You may know those sun-dappled fellows from Vampire Weekend and, certainly, your patience with "Blurred Lines" has grown thin, but how versed are you in the songs of neo-country crooners the Avett Brothers or funk-soul revivalist Black Joe Lewis?

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Nine performers you should know | The house that FreeFest built

Enter our FreeFest primer -- everything you need to feel more in-the-know than a music blogger. First up, check out the set times, then read about our picks for the festival and then listen to the one (or two) songs you need to know before you go.


Chvrches. (Photo by Eliot Hazel)

Scottish electro-poppers Chvrches (look cooler: pronounce it "Churches") are riding into Merriweather on a wave of buzz, having been anointed by no less than the BBC as one of a handful of bands forging the "Sound of 2013." Lead singer Lauren Mayberry's wisp of a voice cuts like glass through her bandmates' hard-driving synthesizers, but the band is no slouch when it comes to lyricism either. Mayberry has a law degree and a master's in journalism.
Set time: 2:15 to 3:15 p.m. (West Stage)
Catch them if you're a fan of: The Knife, the XX
The song to know: Upbeat dance single "Recover" plays like three glorious minutes in a moon bounce. Expect the rest of the set to veer toward the lesser-known tracks off the trio's first full-length album, "The Bones of What You Believe," due next week.

Black Joe Lewis
Listening to Black Joe Lewis can make you feel like you've ingested something illegal and joined the mud dancing at Woodstock. The Austin rocker and his band, the Honeybears, unabashedly channel such '60s giants as Sly and the Family Stone and Jimi Hendrix.
Set time: 3 to 4 p.m. (Pavilion Stage)
Catch him if you're a fan of: The Black Keys, White Stripes, James Brown
The song to know: "Skulldiggin." Heads will be banging as soon as rhythmic keys usher in this wailing, three-minute rager off Lewis's weeks-old album, "Electric Slave."

Pretty Lights
The alter ego of producer Derek Vincent Smith has more in common with '90s trip-hop than with today's screeching dubstep, delivering woozy, soul-soaked sample hurricanes made for fans turned off by EDM's rapid-fire beats and big drops. Another reason this act is a festival favorite: an eye-popping light show torn from the Pink Floyd playbook.
Set time: 8:30 to 10 p.m. (West Stage)
Catch him if you're a fan of: DJ Shadow, Girl Talk
The song to know: "I Can See It in Your Face," a sassy march from 2010's "Making Up a Changing Mind."

The Avett Brothers

Scott Avett of the Avett Brothers. (Photo by Kyle Gustafson for The Washington Post)

Like fellow modern-day jug bands Mumford & Sons and the Lumineers, these North Carolina Americana heroes -- together for more than a decade -- have climbed the charts by shining the tarnish off old country tropes till they feel new again. The Avetts, however, are more inclined toward plainspokenness and spare compositions than their suspender-wearing counterparts.
Set time: 7:30 to 8:50 p.m. (Pavilion Stage)
Catch them if you're a fan of: Mumford & Sons, Josh Ritter, Lambchop
The song to know: "Brooklyn, Brooklyn, take me in," brothers Scott and Seth plead memorably in "I and Love and You," the band's breakout hit. You'd never know it from a casual listen, but the Avetts regularly turn to mega-producer Rick Rubin, the mastermind behind Kanye West's "Yeezus" and The Beastie Boys' "Licensed to Ill," to make magic of their sound.

Although not as well-known stateside as his dance-music compatriots Benny Benassi and David Guetta, Italian-born DJ Rocco Rampino can get a party started, ratcheting up heart rates with pitch-shifting electro-house that will have you hunting for a glow stick.
Set time: 4:20 to 5:50 p.m. (Dance Forest Stage)
Catch him if you're a fan of: David Guetta, DeadMau5, Diplo
The song to know: "Babylon," a favela-inflected banger that took the club circuit by storm a couple of years ago.

Sky Ferreira

Sky Ferreira. (Photo by Hedi Slimane)

It's difficult to discuss the 21-year-old Ferreira and not dwell on her razor-sharp Deborah Harry cheekbones or her flawlessly sullied Kurt Cobain hair. The pop star is a cover girl. Our misplaced focus might be explained by the fact that the singer's oeuvre consists of just two EPs, and a buzzed-about debut album, "Night Time, My Time," that no one has ever heard (it's finally scheduled to drop next month). And this week, the singer was arrested on charges of drug possession, though a representative told The Post she will still play FreeFest. All this aside, at her best, Ferreira can sound like dance star Robyn.
Set time: 1 to 1:45 p.m. (West Stage)
Catch her if you're a fan of: Madonna, Robyn, Charli XCX
The song to know: Technically, it's Ferreira's minor hit "Everything Is Embarassing." But better for dancing is "Lost in My Bedroom," a whirring, Depeche Mode-esque track off 2012's "Ghost" that has her cooing to an unnamed lover, "Don't disappear / It's
just what I imagined."

Robin Thicke

Robin Thicke. (Photo by Jamie McCarthy/Getty Images)

You didn't think we'd leave him out, did you? The R&B singer scored the summer's hottest dance track with his roller-disco-ready "Blurred Lines" and also managed to land in the hottest water for the song's fuzzy -- okay, neanderthal -- understanding of sexual politics. And then came Miley. The FreeFest crowd will be one of the few to judge whether Thicke can rise above his own din; the singer begged off touring this year, making this weekend's appearance one of only a handful he'll make on the heels of "Blurred Lines."
Set time: 6:45 to 7:45 p.m. (West Stage)
Catch him if you're a fan of: Oh, come on. There's no way you're not going to check him out.
The (other) song to know: "Take It Easy on Me." The second dancefloor-ready track on the "Blurred Lines" album channels Justin Timberlake in the best way (with an assist from producer Timbaland, of course) and has Thicke returning to his finest ladies' man form.

Vampire Weekend
Few can rock boat shoes, cardigans and unyielding optimism like New York prepsters Vampire Weekend, who will effectively serve as FreeFest's biggest act and headliner. This year's "Modern Vampires of the City" album was a galloping, punk-forward effort that showed these perennial college boys could grow up.
Set time: 9:20 to 10:50 p.m. (Pavilion Stage)
Catch them if you're a fan of: Paul Simon, the Dead Milkmen, the Postelles
The song to know: "A-Punk," a two-minute world-music-tinged jammer off the band's 2008 debut, is perhaps Vampire Weekend's most familiar and commercial song. But keep your ears open for the buoyant, horn-driven "Diane Young" (get it, "dying young"?)
off "Modern Vampires." Watch the video below.