Today, Edinburgh. Tomorrow, The World. Acts to look out for

Forget the big names selling a thousand tickets a night in the McEwan Hall, or the opportunistic celebrities using a month in Edinburgh as a adrenalin shot for their flagging careers elsewhere, the real story on the Fringe lies with the new faces.

As the world's largest arts festival celebrates its 64th birthday, it's still the greatest gathering of new, young talent on the planet. This year there are 2,453 shows in 259 venues across the city, up from 2,098 shows last year. And, up from 18,901 in 2009, there are an estimated 21,148 performers thronging the streets, many of them hoping for their big break.

Following them around are legions of television producers, talent scouts and journalists, all hoping to snare the next big thing before anyone else.

The Edinburgh Fringe has always been a crucible for new ideas and fertile ground for star-spotting. What happens here sets the tone for what happens next in the arts. It was in the city, in 1960, that Alan Bennett, Peter Cook, Dudley Moore and Jonathan Miller first tried out their subversive brand of humour in Beyond The Fringe. Here, a fresh-faced gang of Cambridge students – Emma Thompson, Stephen Fry, Hugh Laurie and Tony Slattery – won the first Perrier Award for comedy in 1981. Harry Hill, Steve Coogan, The League of Gentlemen and The Mighty Boosh were all spotted here, sweating under the lights in a room somewhere in the Old Town. In theatre, Tom Stoppard's Rosencrantz and Guildenstern are Dead premiered here in 1966, Theatre de Complicité made their name with a Perrier win in 1985 and Jerry Springer: The Opera first caused controversy in 2002.

More recently, Russell Brand and Alan Carr have played tiny rooms on the path to stardom while the international theatre mega-hit Black Watch was first seen in the city's Drill Hall four years ago. This year's success stories are still up for the making. At the end of the first week, there are already names being bandied around in the pubs and streets that no-one had ever heard a week ago. That's the beauty of the Fringe – you can always say you heard it here first.

John-Luke Roberts

The comdeian makes his solo debut with a show that combines killer punchlines with murder. In between routines where he insults his audience, row by row, showcases his character comedy with figures such as Sexy Judge and Shy Zombie and attempts an "irresponsible Kate Bush sketch", we're led to believe that he is committing a brutal murder off-stage. Roberts, who reached the finals of the 2005 BBC New Comedy Awards and writes for Radio 4's News Quiz, is with The Invisible Dot company who last year produced the shows of both Edinburgh Comedy Award winner Tim Key and Best Newcomer Jonny Sweet.

Doc Brown

He's better known as Zadie Smith's younger brother, Ben, but with this, his first full-length show at the Fringe, Doc Brown is making a name for himself in comedy. In his own words, "a washed-up rapper with a social studies degree", his hour combines hilarious take-downs of hip-hop braggadocio (one rap is dedicated to his old-school overhead projector), rap battles with the audience and songs wishing David Attenborough was his grandpa. It also provides a insider's view of pop – Smith was Mark Ronson's hype man and toured with him, Lily Allen and Amy Winehouse for years. You get to see Zadie's child-modelling photographs, too.

Bo Burnham

Without doubt, the stand out discovery of this year's Fringe. The lanky 19-year-old Justin Bieber lookalike started out making videos in his bedroom to amuse his older brother. Sixty million YouTube hits later, he's huge in America – a best-selling album artist, the youngest comedian to record a Comedy Central special and Judd Apatow's protégé (they're writing a High School Musical spoof together). His show, a mix of un-PC songs, hammered out Ben Folds-style at the piano, raps, haikus and one-liners is accomplished, original and very, very funny. "I'm a young comedian. I hate that term," he says. "I prefer prodigy."

Scott Turnbull

The star of Apples, a boisterous play about the lives and loves of a set of school children on a Middlesbrough council estate, or "sex and the city, when you're 15". Richard Milward wrote his debut novel when he was just 20 and it's given a lively production here by Northern Stage and Company of Angels. Turnbull is the touching, stand-out star as the hero, Adam – an inexperienced and geeky teenager with mild OCD and a head full of dreams, who falls in love with the school sweetheart, Eve.

Ella Hickson

Ella Hickson's third play at the Fringe, Hot Mess, is a hot ticket. Set on the basement dancefloor of Edinburgh's swankiest nightclub, Hawke and Hunter, it weaves an intoxicating tale of four twenty-somethings on a night out. At 25, Hickson is no stranger to the Fringe. Her debut play Eight opened here in 2008 and transferred to the West End. She's now working with the BBC, the Royal Court Theatre, the Traverse and Working Title on future projects. Catch her at the Fringe while you still can.

Sara Pascoe

There's something of a female Russell Brand to Sara Pascoe. A gangly, awkward physical performer with mumbly Estuary English, she also has a vivid imagination and a wicked way with words. Her debut hour delivers odd flights of fancy about being Nietzsche's lover, and a Lady Gaga spoof, "Just Read", played on the ukelele. She's divided the critics in the first week but is clearly one to watch for the future.

Frances Ya-Chu Cowhig

The young Chinese American playwright won the Yale Drama Series award for her first play, Lidless. David Hare described it as "an extraordinary and original attempt to show the enduring strain on the victims of the US's deployment of torture at Guantanamo". It's the story of Alice, an interrogator at Guantanamo Bay, who has managed to block out with pills what she did there, and Bashir, a former detainee. Fifteen years on, they meet again.

Belt Up

Fresh out of York University, this thrusting young company are fast becoming a Fringe must-see. Winners at the National Student Drama Festival, this year they have brought eight productions to the Fringe, staged from morning to midnight in the scruffy, fire-damaged attic of C Soco. Whether Antigone or Kafka's Metamorphosis, the focus is on site-specific atmospherics and discomfiting the audience. Some canny producer should find them an empty building in the West End – and quickly.

The Boy With Tape on His Face

Stand-up comedy with no talking. There's a loud buzz gathering around the Fringe debut of New Zealand clown Sam Wills, who performs with black tape across his mouth as the Amelie soundtrack plays. It's classic silent comedy with a twist, imagine Marcel Marceau teaching you the moves to "Blame it on the Boogie" and you're halfway to understanding the appeal of this compelling act.

Abandoman

The new Flight of the Conchords? Having already won the Hackney Empire New Act of the Year and Musical Comedy Awards in London, the duo are selling out to whooping audiences at their first Fringe. Abandoman, "Ireland's seventh-biggest hip-hop crew" (out of nine) are Rob Broderick and James Hancox, who over the course of an hour improvise a mixtape of the best songs never written, based on suggestions from the audience. Lightning quick, it has to be seen to be believed.