A former school teacher who once played drums in Stephen Harper's occasional rock band has been sentenced to two years in jail on sexual exploitation charges.

Phillip Nolan pleaded guilty in October to two counts of sexual interference involving a 13-year-old girl.

Police said the incidents dated back to 1990 and 2000.

In February 2014, Nolan was charged with five counts each of sexual assault, sexual interference and sexual exploitation of a minor.

Nolan was a music teacher who taught Grade 7 and Grade 8 students.

He was also one of three regular members of Herringbone, a Celtic folk band that backed up then-prime minister Harper, who played keyboard and sang in live performances in Toronto, Ottawa and Calgary.

At the time of Nolan's arrest, Harper's office expressed shock at the news.

Harper had known Nolan and the other band members for years; they played at the prime minister's residence at 24 Sussex Drive. They also played together at the National Arts Centre in 2009, when Harper made his unexpected musical debut.

The band's website said Nolan had been involved in the music industry since getting a bachelor of music degree from Queens University in 1994. He worked in musical theatre, both as a musician and as an actor, dancer and singer. He also directed award-winning school bands.