Judas Priest frontman Rob Halford is holding out hope for a collaboration with Lady GaGa after meeting the pop superstar backstage at a recent gig.

The Breaking the Law rocker met Gaga for the first time when he was a guest at a recent concert in San Diego, California - and now the odd couple is making plans to hit the studio together.

Halford says, "I've been a huge fan of Gaga since she first burst on the scene. I just love everything that lady represents. First and foremost, her voice is extraordinary. I love her voice. She's an accomplished musician, she plays piano really well, she's just a great songwriter. And she's a beacon of hope for a lot of people in the world.

"(Meeting her) was a real moment come true. We didn't really have much time to talk. She's busy. I'm busy, but we've agreed to get together at some point and just hang out and maybe do something. I don't know if that will ever happen, but I love her to death."