text: It is the first time an unsigned artist has won the honour - which has previously gone to Adele and Sam Smith.
  "I can't believe this is happening," said the 23-year-old, from south London. "It's all just so ridiculous!"
  Four of the top five Sound of 2017 acts are black British women, reflecting a rise of female talent in grime and R&B.
  Ray said she wanted her music to "empower women to live life as they want".
  "There are so many societal pressures on women, on how we should behave, and they're all based on male privilege."
  The Sound of 2017 list was chosen by a panel of 170 DJs, critics and festival bookers.
  Among them was Jamal Edwards, whose SB:TV YouTube channel has helped launch the careers of Dizzee Rascal, Stormzy and Ed Sheeran.
  He said he was "blown away" when he saw Ray BLK perform at one of his club nights last year.
  "She is the whole package," he said. "I know she's going to have an amazing year."
  "Some artists have that magic about them," said Radio 1's Huw Stephens. "She has a real, raw talent that cuts through so strongly. She is the real deal."
  Born in Nigeria and raised in London, Ray released her first recordings while studying for an English degree. She worked in an advertising agency to sustain her career in its early days.
  Combining her love of hip-hop and R&B, she delivers streetwise, literate lyrics with a velvety soul voice. Her standout track, My Hood, is a bittersweet love letter to her home town, Catford.
  "The south east is one of the roughest places in London but it rears the strongest people, and that's what makes us special," she said.
  The singer has avoided signing a record deal in order to retain the rights to her music, which she releases on her own label.
  Like an increasing number of artists, from Paul McCartney to the Pet Shop Boys, she works with a company called Kobalt Music Services - who provide "back-room" support like publishing and distribution, without tying musicians to restrictive contracts.
  "I feel as though I need to have my autonomy for now," Ray told the BBC.
  "There've been so many artists in 2016 that came out, who did so independently and experienced a lot of success. I think there's a new wave of people doing that. The industry is changing."
  The winning soul singer, whose real name is Rita Ekwere, beat blues singer Rag N Bone Man to top the Sound of 2017 list, while third place went to pop star-in-waiting Raye.
  Ray said: "I'm particularly proud to be a part of this year's list as it's full of so much talent, some of whom are independent artists like myself which I really hope inspires the next generation."
  The Sound of... list launched in 2003 and has a track record in championing new and innovative acts, including 50 Cent, Haim, Frank Ocean, Ellie Goulding and Florence + The Machine.
  According to the rules, acts on the longlist should not be well known - so talent show contestants and members of famous bands launching a solo career are excluded.
  Artists must not have had a UK top 20 single or album before 30 October 2016 - although guest vocalists remain eligible.
  Last year's victor was Jack Garratt, whose debut album Phase entered the charts at number three. He praised the "very diverse" range of acts on 2017 longlist, which also included agitprop rock band Cabbage and folk-pop ingenue Maggie Rogers.
  "This list shows it is possible to have a great ear for melody and not just write the same four chords in different keys.
  "2017 is going to be such an incredible year for art, especially given how terrible 2016 was for politics.
  "We've all got a lot to write about and I think we're going to write some incredible stuff."
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target: Soul singer Ray BLK has topped the BBC's Sound Of 2017 list, which aims to predict the most exciting new music for the year ahead.