Heather Alexander goes behind the scenes for rehearsals and the big night
At least 90 musicians from more than 30 different countries have given their first performance in the YouTube Symphony Orchestra in New York.
The video-sharing website held a contest that allowed anyone, anywhere to upload a clip of themselves playing. A selection went to a popular vote.
The winners were flown in to play at Carnegie Hall - one of the most prestigious venues in the world.
Colombian trombonist John Wilson Gonzalez said it had been "marvellous".
"It was unimaginable that I could get to play in Carnegie Hall, a mythical theatre where only the great musicians play," he told the news agency AFP.
The musicians came from as far away as Australia and South Korea and were aged between 15 and 55.
Some had never left their home countries before, let alone played in such a high-profile venue - and they had just three days to practise before Wednesday evening's concert.
They performed an extensive programme that included works by Bach, Mozart, Villa Lobos, Wagner, Tchaikovsky, Lou Harrison, John Cage, and a specially written piece called Internet Symphony No 1, Eroica, by Chinese composer Tan Dun.
The orchestra is led by San Francisco Symphony Orchestra music director Michael Tilson Thomas.
Musicians were selected in a vote by YouTube viewers
"We're going to give a terrific show at Carnegie Hall that will have some very new and different things about it, both in the way it sounds and the way it looks," he said ahead of the performance.
"But really the most important part of this is how the world out there on the internet will be experiencing that and that will be developing over time as more edits and more uploads take place."
Over 3,000 posted audition videos, and 200 finalists were selected before YouTube viewers voted for the winners.
Cellist Pierre Charles, a 27-year-old student from Paris, said that during rehearsals "the sound was right straight away."
"I was astonished because I thought it would take a lot longer to get ready," he said.
Some of the other musicians said they hoped the concert would help classical music reach a wider audience, including more young people.
"It's not as exciting as [music video game] Guitar Hero or [rock band] Van Halen, so whatever we can do to make classical music and acoustic live music more prominent is a good thing," said Jonathan Brummel, a professional trombone player from California.
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