Lady Gaga has astounding "energy and intelligence", says Tony Bennett.

The flamboyant singer recorded a track with Tony for his album Duets II. The veteran musician was astounded by how talented the 26-year-old singer is.

"I [think she has] the possibility of becoming the Picasso of music. She's very, very talented," he said. "She's different to any performer I've met during my whole career because she recreates herself on a daily basis. I can't believe her energy and her intelligence."

Tony also worked with the late Amy Winehouse on the record and was devastated when she passed away following an alcohol binge last year.

Amy fought drug addiction and Tony has been outspoken on the subject. He dabbled in illegal substances when he was a young man and thinks drugs should be legalised.

The 85-year-old star believes that until that happens musicians will always fall foul of addiction.

"I was smart enough to stop at a young age. It happens to all performers you know... you get helium in the brain once you become successful. You make a lot of wrong moves at first," he told the BBC.

"I just think it should be legalised. I notice in Holland they do that and it's more controlled. You get rid of the underworld selling drugs if you have to go to the doctor to get a prescription I think it would be much more sensible."