It's one of the most popular new shows on television and now Glee is having a profound effect on this year's Edinburgh Fringe.
Shows like The West End Glee Club, the Singalong Glee Club and Showstopper: The Improvised Musical have been selling out across the city.
The multi award-winning TV series, about a gang of high school misfits who join the school's show choir - or Glee club - and serve a weekly helping of re-invented classic songs and big musical numbers, seems to have reinvigorated interest in music theatre at the Fringe.
The West End Glee Club at the Zoo Roxy even has a touch of The X Factor thrown in for good measure, as the audience is asked to vote for one of the four young singers to sing the solo at a fictional UK Glee Club Competition.
The performers, three of whom have the pre-requisite realty show sob stories, rattle through an hour's worth of material from West End musicals like Rent, Wicked, Les Miserables and even an old Queen number.
The cast is made up of recent graduates and member Lisa Lynch says: "We all get to sing our favourite musical songs, like all the typical big numbers."
Cast mate Stephanie Ticknell-Smith agrees that Glee has been a huge influence on the show.
"The first episode I saw, I fell in love with it instantly because it's just like a typical day for us. Most TV shows you can't really relate to, but that one we can."
But full houses are not guaranteed at the Fringe and the increase in competition for audiences, especially in a year when the number of free shows has risen, means the cast spends the day handing out flyers.
"We've had to work hard on the Royal Mile to sell tickets but it's been selling well and the Glee thing is definitely part of it," says Craig Barlow.
At the Gilded Balloon venue, hundreds of people shout suggestions at the stage during a performance of Showstopper: The Improvised Musical.
The hour and a half-long show features a cast who start from scratch with a theme for the musical and some styles of songs that will make an appearance at some point.
"Space," one person shouts out, "the Mafia," someone else suggests. The producer, played by Sean McCann settles on the theme of the Cosa Nostra and a lucky fan who suggests Mafia Mia! as the title of the show is rewarded with a mug.
'Fringe for everybody'
Adam Meggido, who takes the central role of Tony in the musical, says some of the audience remain suspicious about the level of improvisation.
"It's amazing how may people are sceptical about it," he says. "They say: 'How much of it is improvised? I bet it's rehearsed isn't it?'"
The packed theatre is testament to the renewed popularity of the genre, particularly among younger fans.
Meggido says: "We get a good young crowd for sure but we have had people of all ages see the show.
"For the last 15 years or so reality TV, The X Factor and now going into Glee, has created a huge revival of interest in performance."
McCann says that the TV programme is undoubtedly attracting Fringe patrons to shows they may not have bought tickets to in past years.
"One of the lovely things that Glee has done, whatever you think of the show, it plays on big strong human emotions," he says.
"Yeah, there is a lot of the comedic stuff but underneath it all, it deals with mighty feelings of joy and grief and excitement. I like the balance it strikes. It's got heart."
Some of the other musicals taking place at the Fringe this year include Obama Mia!, a show about the US president, Broke Britannia and a rock opera about 70s porn actress Linda Lovelace.
But Fringe chief executive Kath Mainland plays down the effect Glee seems to be having on the increase in musical shows.
"I haven't personally noticed a Glee effect," she says. "I think there are lots of young people taking part in musicals. It is a big part of the Fringe.
"But there is something at the Fringe for everybody, all genres, all art forms, young and old.
"There has always been a big tradition of musical theatre on at the festival and I think this year there are some great ones too."
The West End Glee Club is at the Zoo Roxy until 30 August. Showstopper! The Improvised Musical is at the Gilded Balloon Teviot until 30 August.