The headliners may get top billing on the posters, but in the aftermath of Coachella 2016's first weekend, the buzz has been all about the guest stars. From Angus Young's rousing – and nicely synergistic – turn alongside Guns N' Roses, to Rihanna's cameo with Calvin Harris, the fest was jam-packed with surprise appearances. Here are some that have defined the fest so far.
Kanye West crashed a pair of Coachella sets Friday, performing "Father Stretch My Hands" with A$AP Rocky and cameoing during Jack Ü.
Not only did Rocky surprise the crowd by bringing out Kanye, Schoolboy Q took the stage to perform "Electric Body."
Rising R&B star Gallant brought out Seal for a special duet of the singer's 1990 hit "Crazy," and the two also performed Gallant's hit, "Weight in Gold."
Gangsta Boo joined the hip-hop group for their bawdy, "Love Again."
Run the Jewels had a slew of special guests, including Nas, who ripped a clanging remix of "Made You Look" and called RTJ his "favorite group."
The hip-hop supergroup was full of surprises during their set, including having Bernie Sanders on the big screen. The presidential nominee's visage was greeted by wild cheers, and he let the crowd know that "one of the highlights of running for president […] has been getting to know Killer Mike."
Ice Cube was joined onstage by his onetime collaborators DJ Yella and MC Ren, ripping into "Straight Outta Compton," "Dopeman" (with son and film likeness O'Shea Jackson Jr.) and the notorious "Fuck Tha Police," which Cube claimed he'd been warned backstage not to perform.
The two sang Panic! at the Disco's "I Write Sins Not Tragedies" together.
After Ja Rule shared the stage with Matoma, the Norwegian DJ brought out Sean Paul to perform their new collab, "Paradise."
Norwegian tropical house DJ Matoma (real name: Tom Stræte Lagergren) brought out Ja Rule to perform Matoma's chart-topping remix of Notorious B.I.G.'s "Old Thing Back" as well as his 2001 hit, "Always on Time." Afterward, Matoma brought out Sean Paul to perform their new collab, "Paradise."
Howard and Guy Lawrence had Smith join them onstage for "Latch' and "Omen."
The duo had Lorde join them for "Magnets."
Janelle Monáe wore a shirt that read "Wild Feminist" to sing on their duet, "Venus Fly."
Snoop arrived on a low-rider bicycle draped in a robe and jewelry to flow with style through "Go to Church" and Dre's solo epic, "The Next Episode."
Mysterious producer Zhu brought out Bone Thugs-N-Harmony's Krayzie Bone and Bizzy Bone to help out with 2015 single "Hold Up, Wait a Minute."
Common joined Cube on the new "Real People."
The Danish singer joined Major Lazer to belt out "Lean On."
Kesha made a semi-surprise stop when she appeared during Zedd's Saturday night slot to perform "True Colors."
RiRi joined DJ (and current Taylor Swift flame) Calvin Harris to belt out their collaborative 2011 smash, "We Found Love."
The Bridesmaids star, who danced to "Chandelier" at the 2015 Grammys, showed up to reprise that role during "One Million Bullets."
Eagles legend Joe Walsh and fellow guitarist Glenn Schwartz – an early musical idol of Walsh's, who left the James Gang before Walsh joined – joined Dan Auerbach's Arcs for a blistering jam.
Shortly after news dropped that Axl Rose would be fronting AC/DC on its upcoming Rock or Bust tour dates, Angus Young himself dropped by GN'R's Coachella set to help out with Seventies AC/DC classics "Whole Lotta Rosie" and "Riff Raff."
Trap trailblazer T.I. joined boom-bap revivalist Anderson Paak to perform "Bring Em Out" and "About That Money," singles from 2004 and 2014, respectively.
Canadian singer Kiesza was one of several high-profile guests to appear during Jack Ü's set, joining the duo for a reprise of their 2014 collaborative single "Take Ü There."