Duo go from the depths of despair to the top of the singles chart

(CHRIS LOBINA/SKY1 HD)

They don't have a record deal or a manager, and have only performed in public twice. But two music students are heading for number one after their raw song about recovering from drug addiction became a surprise hit online.

Katie Pepper, 23 and Emma Alkazraji, 30, who perform as Pepper & Piano, showcased their song "You Took My Heart" on Must Be The Music, a Sky One talent show, on Sunday.

Viewers responded immediately to the ballad, sung by Ms Pepper but written by Ms Alkazraji. The song details how playing music helped Ms Alkazraji overcome years of drug abuse.

Within minutes of the show's conclusion, the track began racing up the iTunes singles chart. To the astonishment of the duo, who have completed the first year of an HND music performance course at Trafford College, in Manchester, the song continued to rise up the rankings and reached number five in the official midweek UK chart yesterday.

Lily Allen, a critic of the humiliation meted out to pop hopefuls by programmes such as The X Factor, has urged her Twitter followers to get Pepper & Piano to number one. Their path to the top is currently blocked by Olly Murs, an X Factor runner-up.

"The last few days have been a whirlwind," said Ms Pepper. "We're just a couple of music students from Manchester. We've got no record label or manager and now we're competing against all these huge names in the top 10. We've enrolled to go back to college but that might change if we get to number one."

Their college tutors urged them to try out at a local audition for the talent show after hearing Ms Pepper sing Ms Alkazraji's song. Ms Pepper said: "I cried when Emma first played me the song. People are telling us that song has helped them through their own difficult times and it's great that it can be an inspiration to others."

Before Sunday, Pepper & Piano had only performed in public once before – at the audition for the show. The pair's next gig will be in front of 6,000 fans at Wembley Arena, after they were voted through to the show's final, where a £100,000 prize awaits the winner.