The debate in British music circles this week is whether organizers made the right decision when they booked U.S. rapper Jay-Z to headline this summer's Glastonbury Festival.

The outdoor music festival, set for June 27-29, usually sells out within hours, but this year, tickets are still on sale a week after they became available.

Noel Gallagher, the outspoken guitarist of former Glastonbury headliner Oasis, blamed poor ticket sales on the decision to lead with Jay-Z.

"Glastonbury has a tradition of guitar music," he told the BBC earlier this week. "Even when they throw the odd curve ball in on a Sunday night, you go 'Kylie Minogue? I don't know about it.' But I'm not having hip-hop at Glastonbury. It's wrong."

Jay-Z, the American hip-hop star and former CEO of the popular rap label Def Jam Records, has a large following in North America and is known for hits such as Dirt Off Your Shoulder and Show Me What You Got. He will headline the festival with Muse and The Verve.

On Tuesday, festival organizer Emily Eavis struck back at her critics in an interview with the Independent newspaper, saying Jay-Z would "shake everybody up."

Eavis, daughter of Michael Eavis, the creator of the festival, and now co-organizer of the event, said the festival has always been about presenting challenging and different music.

It's also had hip hop before, including bands such as Cyprus Hill and The Roots.

Media criticism of her choice of Jay-Z reflects a conservative streak among the British public, she said.

"There is also an interesting undercurrent in the suggestion that a black, U.S. hip-hop artist shouldn't be playing in front of what many perceive to be a white, middle-class audience," she wrote in the Independent. "I'm not sure what to call it, at least not in public, but this is something that causes me some disquiet."

Eavis also dismissed rumours that Jay-Z would pull out over the controversy.

"He's definitely playing!" she said. "We've become a tight ship with his management, and we're on a mission to pull something great off."

There was similar opposition when the Smiths were booked to headline in 1984, a concert now considered one of the best Glastonbury performances of all time, Eavis said.

Oasis was a headline act at Glastonbury, now in its 38th year, in 1995 and 2004.

Fan and music blogs in the U.K. were buzzing over the controversy, with some agreeing they didn't want to hear Jay-Z but others saying the poor ticket sales may have more to do with the mud and poor weather that plagued the last three festivals.

with files from the Associated Press