Lady GaGa called Julie Andrews before performing at the Oscars.

The 'Do What U Want' hitmaker sung a medley of tracks from the 'The Sound of Music' - made famous by the legendary actress - at last month's Academy Awards ceremony and called the 79-year-old star to check she wasn't ''offended'' by her choice to sing hits from the musical.

She said: ''She called me about 10 days before and she said, 'I just want to talk to you and make sure I don't offend. That what I'm doing is okay with you.' It was very generous of her.

''She said she'd been working so hard and she was singing everything in my keys. I said, 'Why? They're very high, even for me.' And she said, 'Because I wanted to honour you, so I did them in your keys.' That seemed like going one step beyond any place she needed to go.''

Julie - who starred in the 1965 hit film - was incredibly impressed by the 28-year-old singer's performance, insisting she ''hit it out of the ballpark''.

She told PEOPLE magazine: ''She hit it out of the ballpark. And then she was gracious enough to hand it to me. So that's a really wonderful thing to do too I think.

''As they say in Hollywood jargon, 'She rates tall in my book.''