This time, the 165 tastemakers each picked their favourite three new acts, and those with the most votes made it onto the list.
The participants ranged from magazine editors and newspaper critics to DJs and radio and TV producers.
A longlist of the top 15 artists was published in December, and the top five have been revealed this week.
Theatrical pop singer Marina and the Diamonds is at number two, followed by Manchester trio Delphic, who mix indie guitars with euphoric electronica.
At number one, Ellie Goulding was discovered at a talent contest in her home town of Kington, Herefordshire, and began as a traditional acoustic singer-songwriter.
But while studying drama at university in Canterbury, Kent, she hooked up with dance producers Frankmusik - who appeared on the Sound of 2009 list - and Starsmith, and the results soon gained a following on MySpace.
Goulding has also received the Brit Awards' Critics' Choice prize and said she was "absolutely honoured" to be at the top of the Sound of 2010 list.
"I didn't expect to get anywhere a few years ago," she said. "I didn't even expect to have a record deal, let alone be put in such a prestigious thing so I'm very happy. I think the list this year is great and I really believe in a lot of the acts."
She said she was one of a number of artists who were attempting to usher in a new musical era in 2010.
"I think it's got to that point where bands are committing to the future and creating a new sound," she said.
"I'd like to be one of them. As much as I'm respecting old music, I'm also looking to the future and I think a lot of other bands and artists are doing the same."
BBC Radio 1 DJ Huw Stephens, who has championed the singer, said: "I think what's exciting about Ellie Goulding is her hybrid of electro, pop, acoustic songwriting, all blended together. It sounds effortless, it sounds timeless and it's exciting.
"She's got a beautiful voice, and when you layer that next to the electronic production, it really stands out from the crowd."
The Guardian's Paul Lester, the first mainstream music critic to write about Goulding, in his
New Band of the Day
column, was among the pundits who voted for her.
"I picked Ellie because someone I rate - Frankmusik - told me she was great, and he was right," he said.
"I like the way she's really versatile. You get the impression she could do folk as well as she could a dubstep track.
"As far back as the summer, people were touting her as the next big name. She looks good, she's got a good story and her songs are great - haunting, ethereal, but somehow catchy, like Cocteau Twins go pop, or something."
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