Joseph Gordon-Levitt is getting great reviews for his new flick, "Don Jon," and he just handed out his own two-thumbs-up review to singer-turned-actress Lady Gaga.

Gordon-Levitt revealed that the Mother Monster has a cameo in Robert Rodriguez's "Sin City"

The actor opened up about the cameo to radio station Jam'n 94.5days after he was spotted chatting with the Mother Monster during Sunday's MTV Video Music Awards. (She performed at the show and he presented Justin Timberlake with the Video of the Year Moonman.)

"She was in 'Sin City 2.' I did a part for [it]. Mr. Rodriguez asked me to be in, and Lady Gaga is in a scene of it. And I gotta say, she did a really good job," the actor said. "Like, she's a great actress. And I didn't know that. You know she came in and I was like, 'OK sure, they're having a huge pop star do a scene in the movie, I understand.' But then she came in and like, nailed it! She had her character down, and she was like a total pro and did a great job. I was really impressed. So it was good to see her again [at the VMAs]."

Gaga and JGL will be joined by A-listers like Josh Brolin, Eva Green, Mickey Rourke, Jessica Alba and Bruce Willis in the flick.

"Sin City: A Dame To Kill For" is slated to hit theaters August 22, 2014, but before then Gaga will not only drop her new album ARTPOP, but will also star in another Rodriguez ...

WANTAGH, NY — There was a time when squealing teenagers would scream for John Mayer.

Don't be mistaken, there are still a lot of young girls going to JM concerts in flower crowns and matching T-shirts, but the majority of the screaming comes from the middle-aged men. These men aren't just the dads of those girls, but they're dedicated fans, there with their wives or buds, screaming, "We love you, John!"

Mayer, on his Born and Raised Tour, shows a decidedly more mature side than his Heavier Things days, drenching his band in denim and tying a weather-worn scarf on his head. An animated background of canyon rocks symbolizes his move to the Montana country, his independence and his folk growth.

"It's a weird thing to grow up in front of you guys," Mayer said in a vulnerable speech toward the end of his set. It's been 12 years since his first album was released, and in 2012 and 2013 he released two more back-to-back, totaling his studio album count to six. Unable to tour for his 2012 LP, Born and Raised, while recovering from vocal surgery, his current tour includes new material from two records, something Mayer is a little insecure about.

"I wonder if anyone cares or connects," he said to the crowd, who would cheer enthusiastically for his older hits like "I Don't Trust Myself (With Loving You)," but rest their bones during the new ones. "It's really uneasy."

John's sprinkled in a few of those crowd-pleasers throughout Wednesday night at Jones Beach, but he rounded out the set with tunes ...

Even months after his departure, most "Saturday Night Live" fans likely associate Bill Hader with eccentric city correspondent Stefon --a role that earned him his second Emmy nomination. And while he may be skipping out on New York's hottest night clubs for his reprisal as Flint Lockwood in that doesn't mean avid Stefon fans won't enjoy the family-friendly flick.

In fact, what initially attracted him to the first "Cloudy" movie is the comedic vision of directors Phil Ward and Chris Miller. And while there were new hands taking the helm this year -- Cody Cameron and Kris Pearn -- Hader knew it would be just as fun the second time around, especially when it involves dinosaur sized monsters made of food.

The sequel picks up right one second after the original movie and progresses into what Hader describes as a "Jurassic Park"-style adventure -- but this time, "foodimals" are the enemies, and they are the offspring of Flint's invention from the first film. Hader described this movie as a "more personal" tale, one that focuses on his friendships and budding romance with weatherwoman Sam Sparks (voiced by Anna Faris). Just look at the tension between the two in our exclusive photo!

"I just thought [the directors] had such a specific voice -- a specific comedic voice, and that they were allowed to do it in a big, animated movie was really exciting," Hader told MTV News as a part our Fall Move Preview. "It was always a fun time."

Well, maybe not always. Voice acting, it turns out, isn't as easy ...

The more we learn about Lady Gaga's ARTPOP the less we know about what to expect. While she's given us some of her classic dance pop with first single "Applause," a rehearsal video the singer uploaded on Thursday (August 29) shows that it won't be all flashing lights and thumping beats.

The one-minute clip is a teaser for Gaga's headline appearance on Monday at London's Roundhouse as part of the month-long iTunes Festival. She teased fans about it on Wednesday with a provocative picture of herself standing next to a dancer who's wearing a metal pig gas mask along with the message, "REHEARSAL PIC #SWINEFEST #GETREADYTOSQUEAL."

What she revealed on Thursday was a snippet of an ARTPOP track reportedly called "Swine," which has a driving, industrial rock groove that's reminiscent of Nine Inch Nails. The teaser opens with Gaga seated at a keyboard singing, "I know, I know, I know you want me/You're just a pig inside a human body," as her band patiently waits their turn to chime in. "Squeal-a, squeal-a, squeal-a you're so disgusting!"

Though the subtle groove continues, the scene changes to Gaga — wearing black tights, a long white t-shirt and a black wig — bashing away at cymbals on a stripped-down drum kit, her hair flying, while playing keyboards with her left hand.

Eventually the band kicks in with a classic rock-like heavy guitar groove that explodes into a galloping industrial sprint, with Gaga continuing to bash away at a cymbal with a yellow drum stick and yelling, "Swine!" Gaga has promised to play ...

Tom Hiddleston won't be back as Loki for but that doesn't mean the God of Mischief is far from sight.

Indeed, Hiddleston rejoins the Marvel Cinematic Universe as soon as November's a project the actor describes as "a sequel to 'Avengers' as much as it is to 'Thor.'" (You can see an exclusive trailer cutdown for "Thor: The Dark World below.)

"It's a roller coaster, no question," Hiddleston told MTV News during our recent Fall Movie Preview interview. "It's full of ups and downs and loop-de-loops and twists and turns. It will take you to places you haven't seen before."

In the upcoming "Thor" sequel, the titular God of Thunder brings his hammer to bear upon Malekith the Accursed, leader of a forgotten foe known as the Dark Elves. "They have an ancient, ancient grudge against Asgard and against the reign of Odin, and they're back," Hiddleston described of the "massive and threatening" enemies facing Thor this time around.

But never count Loki out of the fight. Even as most eyes are turned toward Malekith, Hiddleston's very own mischief-maker remains a thorn in his brother's side.

"Loki has a very complicated relationship with Thor," Hiddleston said of his role in the film. "He is an agent of chaos without equal in the world he inhabits. He knows his true nature. He knows he doesn't belong in the family of Asgard, and he's locked away in the beginning of the film in the deepest, darkest recesses of the dungeon as public enemy number one."

It's not long before foe becomes friend, however, ...

Before Katy Perry gave a knock-out performance of to close out the 2013 Video Music Awards, she gave her fans a taste of what's to come on her upcoming album, Prism.

Fans had the opportunity to choose whether both off Prism, would get an early release on September 17. After several fierce days, Katy Cats voted "Dark Horse," featuring Juicy J, to be the chosen track.

And since fans only got a small taste of "Dark Horse," we asked Perry what we can expect from the track.

"It's kind of a juxtaposition. It's got me, a pop artist, with a little bit of an urban kind of hip-hop-flavored background soundtrack to it, and the lyrics are kind of witchy and dark, as if I was a witch warning this man not to fall in love with me, and if you do know I'm going to be your last," Perry revealed of the Dr. Luke- and Max Martin-produced track, which she wrote with her friend Sarah Hudson in her hometown of Santa Barbara, California. She went on to describe it as having a "witchy, spell-y kind of black magic-y idea."

As for "Walking on Air," fans will have to wait until Prism's release on October 22 to hear the song in full, but she did divulge that the high energy-track came about in an unusual kind of way. It all started when she and a friend were strolling in Central Park and she saw a group of people roller-skating to deep house music.

"I looked at her and I said, ...