(Cover) - EN Showbiz - Lady Gaga was so committed to her alter-ego Jo Calderone at the MTV Video Music Awards (VMAs), she stayed in character for days.

Gaga opened the show, taking to the stage as chain-smoking mechanic Jo Calderone to perform You and I. She remained as Jo throughout the ceremony, but VMA Executive Producer Dave Sirulnick has revealed Gaga transformed into Jo hours before the event.

She arrived to rehearsals in character and even used the men's toilets backstage.

"We had talked to her about the creative [for the performance] a few weeks before the show, Sirulnick told MTV News. "She showed up as Jo, rehearsed as Jo... if you said 'Gaga,' she wouldn't respond. After rehearsals, she comes over, she says to me, 'It's nice to meet you,' and I say to her, 'I know your friend Gaga,' and she says, 'That Gaga, what a b***h!'

"She did not break character once. She walks in backstage and, in front of a whole bunch of people, went into the men's room. Jo was walking out of the building to her dressing room and someone yelled, 'It's Gaga!' But she didn't respond, just kept on walking, until finally someone yelled, 'Hey, Jo!' and then she turned and waved."

Sirulnick was impressed by Gaga's commitment to the character. He has been working on the VMAs for a long time, but insists he has never encountered anything like Gaga's performance.

"Over the years, lots of people have done lots of things, lots of people have worn lots of things, but no one has been that committed, that in character," he laughed. "She's smoking in the building, she was holding court in the crowd, you know, Kanye, Katy, Adele, Tony Bennett, they loved it. They respected her commitment and her level of artistry.

"For her to go out there and just be so into this character, it was fearless." (C) Cover Media