Mark Ronson has been teaching Lady Gaga how to play guitar for her forthcoming album.

Mark Ronson

Mark Ronson

The 'Uptown Funk' hitmaker performed with the 'Born This Way' singer at a Met Gala after-party last week, which was the first time the 30-year-old pop superstar has played guitar properly in public.

Talking about their duet of 'Burning Down The House', Ronson, 40, told Bloomberg's Charlie Rose: "I've been working with Lady Gaga for the past few months on her upcoming record and I am blown away by her talent and her voice.

"I think the opportunity came along that they wanted us to perform at the after-party for the Met Gala at the Apple party.

"She's never played guitar in public before. She's great on piano but guitar is something she is learning for this record. And she just smashed it. I showed her things and she's such a fast learner and as a performer her charisma is insane so she could have carried it anyway.

"It was a very last minute thing and we got to rehearse for one day and it could have gone whichever way wrong. It just kind of came off without a hitch and it was very fun. I am having an amazing time working with her."

Ronson, 40, says Gaga's follow-up to 2013's 'Artpop' will be "authentic and "analog" and won't rely on digital or computer trickery.

On working on the record together, he said: "She is a muso at heart. She's happiest when she is sat at a piano barking orders and that side of her I don't think the world has seen it. It is great to make this very honest, authentic analog kind of record."

The DJ-and-producer feels like there is a real lack of authenticity in pop music and has praised Adele, who he worked with on her latest LP '25', for being an honest and true-to-herself artist.

On working with the 'Hello' hitmaker, he said: "She calls me every six years. I hope I get the call for 31.

"Adele's voice is so instant. I feel like for somebody who has such a sunny disposition as she has, all of the pain in her voice it is that locks you in right away. She could sing the phone book to us we'd probably line up to buy it. She is a great songwriter and also authenticity is what we are missing right now."