The best SXSW lineup has somehow managed to get even better. As of Saturday, more acts have been added to the event, including: Earl Sweatshirt, Chief Keef, Josh Ritter, Flying Lotus’ hip-hop side-project Captain Murphy, Billy Bragg, Hanni El Khatib, Dillon Francis, Amanda Palmer, Phosphorescent, Weekend, Mykki Blanco, Future Unlimited, Tijuana Panthers and California X.

As we previously reported, Yeah Yeah Yeahs' upcoming album, Mosquito, will arrive on April 16. But in anticipation of the new record, the band on Wednesday released a teaser of a new song along with news that they will be performing a show at SXSW, as part of NPR’s music showcase. They will be performing at Stubbs on March 13, along with Nick Cave and the Bad Seeds, and the event will be streaming via NPR.

Gulf Shores, Ala., is gearing up for another Hangout Music Fest this spring. The initial lineup was revealed early Wednesday morning, with Tom Petty and the Heartbreakers, Kings of Leon and a third headliner (to be announced shortly) leading the pack. The three-day event will, of course, take place once again in Gulf Shores on May 17-19.

More great music news! SXSW has announced a third wave of acts to perform at this year's festival, which will apparently bring together a ridiculous amount of talent. The event, which takes place March 12-17, will now include Vampire Weekend, Eagles of Death Metal, Local Natives, Frightened Rabbit, Tegan and Sara, Black Lips, Wild Belle, The Besnard Lakes, Camera Obscura, Fitz and the Tantrums, Macklemore & Ryan Lewis, Mr MFN eXquire, The Thermals, Icona Pop, Allah-Las, AZARI & III, Bleached, Merchandise, and Psychic Twin.

Following last month's first round lineup announcement, SXSW has confirmed some hefty new additions to its 2013 slate. With only three months to go, the roster is already looking very good. Last month's list included Civil Twilight, Alt-J, The Staves, Gold Fields, Lecrae, David Ramirez, Matthew Perryman Jones, The Dunwells, Atlas Genius and White Lung. Today, even more reason to get excited—with Ra Ra Riot, The Joy Formidable, Alex Clare, MS MR, Angel Haze, Delta Rae, ZZ Ward, Little Green Cars, Lianne La Havas, Skylar Grey, The Heavy, Cold War Kids, Generationals, Dawes, Dessa and Aloe Blacc.

South by Southwest has announced Dave Grohl as the 2013 music keynote speaker. The speech, which is open to Music and Platinum registrants and registered showcasing artists, is scheduled for Thursday, Mar. 14., at the Austin Convention Center.

With only four months to go until the big event, SXSW has announced its first full list of acts performing at the 2013 festival. The Music event runs Mar. 12-17 in downtown Austin, with some favorites already slated to be on the lineup, including Civil Twilight; Alt-J; The Staves; Gold Fields; Grace Kelly; Lecrae; David Ramirez; Matthew Perryman Jones; The Dunwells; Atlas Genius; Guards; White Lung; Said The Whale; and Charlotte Church?

Guess it’s not too early to start planning for next year’s SXSW. Tennis confirmed their appearance on Thursday as part of the 2013 lineup. As of now, they are the first band on the roster. SXSW 2013 is scheduled fo March 12-17, and registration is now open.

The indie outfit is currently one of our FutureSounds in the latest issue of Variance:

Nine years ago, 50 Cent burst into mainstream hip-hop -- with the help of co-executive producer Eminem -- on his proper debut, Get Rich or Die Tryin'.

Fast forward to Friday night (March 16), when 50 Cent revisited the successful album with an anniversary concert, 'Shady 2.0,' at SXSW. At 11 p.m. 50 Cent walked onto the stage of Austin Music Hall wearing a camouflage bulletproof vest, reminiscent of 50's persona circa '03.

About mid-show, Eminem--rumored to make an appearance from the moment the concert was announced-- indeed joined 50 on stage. Both rhymed to "Patiently Waiting" alongside each other, and later closed the show together with 50's freestyle, "Till I Collapse," "Don't Push Me" -- sans Lloyd Banks -- and Eminem's own "Crack a Bottle."

"We out of here," Eminem shouted after thanking those in attendance.

Watch the video below.

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He did it again.

Kanye West made an unannounced appearance during South by Southwest Wednesday night at the Belmont in Austin.

At around 1:30 a.m. local time, West and rapper Big Sean joined 2 Chainz, a new signee to Def Jam, onstage, leading to dozens of flip cams springing up from the surprised audience.

The showcase also featured buzzworthy hip-hop/R&B acts like Machine Gun Kelly, Miguel and Elle Varner. Joe Budden, a member of the headlining rap group Slaughterhouse, apparently tipped fans off to West's impromptu appearance by posting on Twitter, "Just had a pretty deep talk w Kanye..... That was dope."

Watch the video here.