Pop star Miley Cyrus' channeled her inner Hannah Montana by busking on the street in disguise shortly before her Disney show took off.

The Wrecking Ball hitmaker played a teenager living a double life of student by day and pop star by night in the hit kids show, and her elder sister Brandi recalls one final Los Angeles street performance before her sibling became an overnight sensation.

Brandi recalls, "Miley had just gotten Hannah Montana, so she got this crazy idea that she wanted to sit outside of Starbucks in our neighbourhood, unrecognised (for the last time), and play her guitar, with her guitar case open.

"It was like this weird fantasy of hers. She's like, 'I just want to be that person sitting on the kerb at Starbucks, but I can't because people will recognise me'.

"So we put on baseball hats, scarves, big coats, go to Starbucks, had our heads down playing emo (alternative rock) cover songs. No one recognised us, people totally gave us money, and then about 15 minutes in we're like, 'This is working! This is awesome!'

"But then this bigwig at Disney comes up and is like, 'Brandi? Miley?' And we're like, 'No! Shh!' He's taking our picture, sending them to our dad saying, 'Do you know where your daughters are right now?' But we totally got away with it."