Sarah Beattie asks for volunteers to sing the solo and a forest of hands shoot into the air. That would be no surprise in a primary school, but Ms Beattie is a secondary music teacher and the hands belong to teenagers. Adolescent angst may be kicking in, but no one is worried about appearing uncool and there is no fear of feeling self-conscious.
Amy and Adam are the lucky ones this time and step up to the front to take the lead parts. And then something else unusual happens. This is not the traditional school choir repertoire of hymns, folk songs and 1960s pop; this is an acapella version of a 1980s power ballad.
Behind the leads, the girls' chorus peer studiously at the music, intent on getting their bop-bops in the right place. The boys energetically bring up the bass, even though some of them cannot quite reach those low notes yet.
And the reason for this enthusiasm? One word: Glee. The US TV series has become a cult phenomenon since it began airing on the digital channel E4 earlier this year. It follows the fortunes of a high-school show choir and their choirmaster as they attempt to win a state-wide competition. They try to overcome the image of glee club members as losers and the hostility of a PE teacher who does not want the spotlight taken away from her cheerleaders.
Glee clubs have a long tradition in the US, but the popularity of the show here has taken many by surprise. These pupils at Huish Episcopi School, in Langport, Somerset, clamoured to set up their own club after watching the programme.
As Amy and Andy get stuck into "Don't Stop Believin'", a 1981 hit for rock group Journey that returned to the US top ten after it featured in Glee, Ms Beattie says the singers are already bonding, even though it is only their fifth rehearsal.
"The nice thing about the group is that they are all different year groups," she says. "They didn't really know each other, but because they like Glee, they have formed a little group and chat to each other."
The TV version revels in its stereotypes: the quarterback who faces the prejudice of his teammates; the Jewish princess who wants to sing every solo; the gay guy who loves show tunes; and the Asian goth who complains that as the token Asian she only gets the minor parts.
Likewise, cliques are already emerging among members of Huish Episcopi's glee club. There are the eager girls who join every club available; the indie kids who hide behind their hair; the group that fools around between songs; and the boys who do not want to show too much enthusiasm in case it is taken the wrong way. "They will wait and see what everyone else is doing and then join in afterwards once they are sure that it's cool," says Ms Beattie.
For many children, Glee is more than a TV show: it is proof that singing and dancing is credible enough to leave the football team for, as well as being a lot of fun. "I never wanted to admit to my friends that I loved musicals," says 11-year-old Lizzie during the rehearsal break. "But Glee's made it OK to like them. It's funny and some of the people in it are cool."
The pupils' enthusiasm was obvious to Ms Beattie. "They would burst into song after they had seen an episode, and they were asking me to teach songs from the show in their lessons," she says.
After watching a couple of episodes herself, she bought some of the sheet music over the Easter holidays. It seems that Mrs Beattie wasn't the only one: since the programme first aired in the UK, music publishers Music Sales have had record sales of sheet music.
The first rehearsal of the Huish Episcopi glee club attracted 14 pupils. By the second, the word had spread and the number doubled. For Edie, glee club was a welcome alternative to the school choir.
"It's more of a range of music than choir, which is more about hymns," says the 12-year-old. "This is more my kind of thing."
While lovers of traditional school music may shudder at the sentiment, and the apparent ditching of centuries of music, Ms Beattie says the glee repertoire benefits from being immediately recognisable to the majority of pupils. Although the club counts some of the more experienced school musicians among its members, many come to glee with little background in performing.
"A few of them are gifted and talented students and will already play a few instruments, but it's not all the case," says Ms Beattie. "Lots of them will not have sung before in the school."
The familiarity of the songs makes reading music less daunting than it could be otherwise. Some follow the general pattern and phrasing of the notes, rather than reading the pitch. At one point, a pupil asks what the marking "mf" means and finds out it is an Italian term mezzo forte - moderately loud.
"Anything that promotes singing and energises the kids should be applauded," says Toni, a music teacher, on the TES online forums.
"At my current school we had more of a traditional choir, however since the arrival of Glee the children are energised by the way in which popular and older songs have been covered on the programme." Songs from Glee are now included in the repertoire and new members are joining the 70-strong choir every week.
Not surprisingly, adolescent boys are often the most reluctant singers, but at Huish Episcopi, about half of the glee club members are boys. "I really like Glee, and I listen to a lot of music," says Aaron, 14. "[The show] makes a lot of songs upbeat. A lot of people are embarrassed to sing, though - they think it is quite girly." His friend Alex, also 14, says he does not care what people think. "I'm more into metal and punk, but I sing all the time," he says. "I quite like singing this kind of stuff as well."
Glee has clearly made singing cool. Even though they realise they are at the bottom of the school's social pecking order, members of the television glee club are full of confidence in the power of their own abilities. But not everyone is a fan.
Martin Ashley, education lecturer at Edge Hill University in Lancashire and an expert on boys' singing, believes it ignores the physical obstacles to getting teenage boys to sing music written for more mature voices. Puberty will leave many boys unable to sing the bass parts, and taking the female parts will only reinforce the idea that singing is for girls.
"They can't sing like men, and if you ask them to, many of them won't sing at all," says Professor Ashley. "A few extroverted boys might not mind singing the girls' part, but a lot of boys would."
Tim Lissimore, advanced skills teacher in music at Wilson's School in Surrey, agrees that boys can be self-conscious about their voices, but that does not mean they cannot be persuaded to sing. "Self-confidence is everything," he says. "To get boys to sing, it has to start in the classroom and has to be taken for granted."
Mr Lissimore has tried a variety of repertoires and says every group he has taught has come to love singing. "The repertoire has to be appropriate and start with some sort of distraction from the business of singing. For example, singing `Land of my Fathers' with the nationalistic pride of a Welsh rugby fan," he says.
Songs from a popular TV show may be an attractive prospect for teenage boys and a distraction from feeling self-conscious, but boys need to be able to sing it, adds Professor Ashley. "You have got to have a repertoire that matches their voices," he says. He suggests teachers get hold of songs with a "capiata" part for boys of this age - a singing line slightly lower that an alto girls' part. "The range that boys can sing at that age also becomes smaller and Glee doesn't deliver in that. A 12-year-old does not have that kind of voice," he says.
The national Sing Up programme has been at the forefront of making singing a big part of music education in primary schools. But secondary schools rely much more on the individual teacher and music departments. Ms Beattie has noticed a big difference in attitudes to singing, especially with boys, among pupils who have come through the Sing Up programme.
"I probably would have said they were self-conscious a couple of years ago, but I have just done some reggae with Year 8, and all the boys want to sing it - they don't want to play it," she says.
"It was a Bob Marley song, and it's because they have heard it on the radio they want to replicate something that they already know about. More pupils want to sing and it's becoming more acceptable."
Glee clubs may not be the only answer to making sure the love of singing survives the transition from primary to secondary, but the TV show has taken away some of the embarrassment factor attached to singing in public for adolescents.
"It puts people in a better mood and it gives you more self-confidence," says Ms Beattie. "Also, you can see progress quite quickly - they are already picking it up well, because they are so eager to learn."
Once they have a few songs up to scratch and have put some choreography together, Huish Episcopi's glee club will perform at assemblies. They may not yet have regionals in their sights - the aim of their TV counterparts - but that does not seem to matter at this stage. As the last bars of "Don't Stop Believin'" fade away, there are smiles all round and an excited plea: "Can we do it again, Miss?"