Jamie Cullum invited the students to harmonise with him

The rising jazz star held a seminar for sixth-form music students at Sullivan Upper school in Holywood, County Down on Tuesday.

Walking in to cheers from the students, it was clear from the start that Cullum was not a typical music teacher.

"I have no plan or anything, but we'll play some songs and try to get some of you maybe singing or playing with us," he told them.

"If you have any questions about what it's like to be a musician for a living, whether it's cool or not cool, ask what you want to know."

The 26-year-old performed a number of songs for the class and even got them to harmonise with him.

"I'm not trying to preach to anyone, I'm just giving them my enthusiasm for what I do and hopefully communicate it a little so they feel inspired to do it for themselves," he said.

Cullum later played a sold-out show at the Waterfront in Belfast

Music teacher Gary Myles said it was great to have someone like Cullum in to motivate his students.

"Because of who he is, they're more likely to listen to someone like that who has made it, if you like, rather than someone coming in trying to push students in the right direction," he said.

The marketing campaign for his latest album has targeted head girls at every all-girl school in Britain, with them being sent Jamie Cullum promotion packs, including posters, stickers and copies of his new CD.

His record company believes the girls' influence on friends and fellow pupils will help spread the word about Cullum to a younger audience.

One of the Sullivan Upper students, Susie Elks, said she had learned a bit from the unorthodox lesson.

He became a star despite never having formal music lessons

"I sing harmonies at my local church and I guess I will be bringing a little bit of what he taught to that," she said.

Cullum admitted he did not learn much about music when he was at school.

"Most of the music I did was outside school, joining bands and jamming with my brother and trying to copy what I heard on the radio," he said.

Cullum had some advice for any aspiring musicians.

"I would say the most important thing is to get hold of an instrument, either at school or if you're lucky enough to have one at home, and just muck about on it and make noise," he said.