Jay-Z stunned students at a disadvantaged school in Sydney by paying a surprise visit as part of Oprah Winfrey's jaunt Down Under.

The media mogul is currently filming The Oprah Winfrey Show in Australia as part of the programme's final series, and she enlisted the rapper to make an appearance at Canterbury Boys High in south-west Sydney.

Jay-Z was filmed walking into a class in the middle of a music lesson and treating the stunned students to an impromptu jam session and some expert advice.

He later told Winfrey, "I see myself in those guys - people that come from difficult circumstances. I believe in opportunities."

And the talk show host had a further treat in store for the pupils - she vowed to buy a new computer for every student and teacher at the school, joking, "Now there's no excuse not to do your homework!"

Winfrey also promised to help renovate the school's library and music room.