Central Characters, a theatre company of actors with physical and intellectual disabilities, bring a large dose of anarchy to their productions, but they take their art very seriously, writes Róisin Ingle.

Shakespeare missed out on what could have been an iconic scene by not bothering to write a wedding for Romeo and Juliet, according to members of the Central Characters drama group. Six years ago, while adapting its first classical text, the group redressed this omission. A wedding scene was devised and the non-vocal lead, Suzi Queenan, keyed her marital responses to Romeo into a speech machine during the ceremony.

In rehearsals one of the cast felt Juliet was taking too long to say "I do" and ad-libbed: "You can go 50-50, phone a friend or ask the audience." His quip became part of the play's script and went down a storm when it was performed in the Samuel Beckett Theatre in Trinity College, Dublin.

This is how scripts evolve in the hands of the Central Characters, explains director Cormac Walsh. The participants are all adults with physical and intellectual disabilities, such as cerebral palsy, spina bifida and muscular dystrophy, and many are wheelchair users. Walsh has been working with the group since graduating from Trinity's Department of Drama 10 years ago. A trip with the group to Athens as part of the EU's Horizon project formed part of his dissertation. The group, which operates out of the Day Activity Centre at the Central Remedial Clinic in Clontarf, rehearses in nearby Killester College every Tuesday morning. To date, Central Characters has tackled Dracula, Star Wars, The Wizard of Oz and One Flew Over the Cuckoo's Nest. Its current project is a rock opera version of Alice's Adventures in Wonderland, a suitably surreal interpretation which includes music from Pulp, Queen, Guns N' Roses and Handel.

Walsh describes the group's approach to theatre as being inspired by the Commedia dell'arte, a popular form of improvisational theatre which began in Italy in the 15th century. "It was about characters being placed in different scenarios. The performances would develop depending on how each actor felt the character was responding on the night," he says. "We always remain true to the story but the actors bring so much more to each script." For example, in Romeo and Juliet "a plague o' both your houses!" became "yiz are all bleedin' mad".

Characters evolve just as organically. Walsh presented the script of Alice in Wonderland: A Rock Opera and one of the actors, Mary Gaul, put herself forward to play the part of White Rabbit. But then, after some research, Gaul decided she didn't like the bedraggled illustrations of the White Rabbit in Lewis Carroll's book and opted to be a Pink Mouse instead.

She moves around the auditorium in Killester College squeaking convincingly in her wheelchair, wearing a pink poncho, pink watch and furry pink gloves, clutching a giant wedge of cheese. She is focused and determined about everything from her lines to sourcing a pair of pink trousers. "I've searched everywhere, but no luck," Gaul confides.

When the Central Characters get to work, the Queen of Tarts becomes the Queen of Sheba and another actor becomes the King of Spuds. The March Hare, played by Alan Melvin, adopts a perfect cockney accent. "I'm late, innit? For a very important date?" Before launching into an energetic air-guitar solo for Bohemian Rhapsody he explains why he enjoys being a member of the Central Characters. "It's just so vibrant, I feel more alive doing this than anything else," he says.

Alice, played by Natalie Redmond, is well cast and an endearing character as she wanders through Wonderland looking for a way out. Redmond's past roles have included Princess Leia in Star Wars. "What I like is the singing," she says. "It's wonderful, Alice comes out of a dream and the key opens a door and when she sits down she starts bawling her eyes out and the rest of the cast start singing I'm Swimming in the Rain. Her tears make a river."

'Every show works differently," explains Walsh. "There is always a lot of talk at the start, we cast the principals and work out from there. When we were casting One Flew Over the Cuckoo's Nest, Ian Berkery, who is non-vocal but is passionate about the theatre, came whizzing up to me and was banging away at my desk with his chair. I read out the list of characters and when I said 'McMurphy' he rammed the desk so we knew that was the part he wanted to play."

If each show throws up fresh challenges to the group, this was one of the biggest. "We cast an actor, Conor O'Neill, as Ian's voice, so he dressed like Ian does and followed him around voicing the words while walking two steps behind. The other actors had to look at Ian and not at Conor because that's where the energy of the part was coming from. He was McMurphy."

In Alice, Ian Berkery sings Stevie Wonder's I Just Called To Say I Love You using his speech machine, and it's the highlight of the Hatter's tea party.

Each year, drama-studies students from Trinity College get involved with Central Characters as part of a community-drama module of their course. Claire Butler from Dublin is playing Tweedle Dim and says that from a dramatic perspective the experience is exhilarating: "It's live theatre so of course it's challenging. A template is laid down with the story and the actors each add their own flavour. It's exciting because we all bring our different physical, emotional and intellectual states to each performance."

At rehearsals this week in Killester the atmosphere was intense and focused, even though much of the content - their version of Common People is a riot - is hugely entertaining. "Our ethos is not about having craic. We take it very seriously, I've worked with a lot of groups over the years and these are the most unified and the most serious about getting the work done," says Walsh.

Alice in Wonderland will be performed on Monday and Tuesday in the Samuel Beckett Theatre and Walsh says the mixed audience helps to create a special atmosphere. "During the performance those with intellectual disabilities may be shouting up from the audience, directing the cast, while the academics from Trinity sit nodding sagaciously," he says.

Walsh is protective of the group's dramatic integrity and wary of patronising attitudes to their work. "I get a little upset when it's not treated as serious theatre," he says. "We apply pure theatrical techniques to what we do, we have to overcome many challenges to create the piece. When the play begins I honestly don't know what will happen. Sometimes I feel more like a football manager than a theatre director."

"For an audience who doesn't know them it can seem like anarchic mayhem on the stage," says Chrissie Poulter, a drama-studies lecturer at the Samuel Beckett Theatre, which is, incidentally, the most wheelchair-accessible such space in the city. "What is wonderful is that this is a serious, tight-knit group who have been working together for years. The presentation has definitely moved on beyond just 'isn't it brilliant?' and 'aren't they having fun?' Of course it is fun, but it's about much more than that."

Alice in Wonderland: A Rock Opera by the Central Characters runs at the Samuel Beckett Theatre, Trinity College, Dublin on Mon and Tues at 1pm. Admission is free