text: The Californian singer has provided backing vocals for Stevie Wonder, Elton John, Josh Groban, Carole King, Robbie Williams and Rod Stewart in her stellar career.
  Most famously, she was due to be a featured singer on Michael Jackson's ill-fated This Is It tour in 2009 - and can be seen performing a spine-tingling duet with the star in the posthumous film of the rehearsals.
  She went on to appear on the US version of The Voice - where her shock elimination prompted judge Adam Levine to declare: "I hate this country".
  Hill's efforts to launch a solo career were then documented in the Oscar-winning film 20 Feet From Stardom - which turned the spotlight on the (mainly African-American) back-up singers who have propped up rock's biggest stars.
  But the catalyst for her solo career turned out to be Prince - who read about the star in a newspaper, and invited her to record an album at his Paisley Park Studios in Minneapolis.
  Hill tells the BBC about their collaboration, her experiences as a backing singer, and the day that Michael Jackson died.
  What's the first song you remember hearing?
  Walk With Me by Vanessa Bell Armstrong
  Who was the first person who told you you could sing?
  My mother was the first person to tell me I could sing.  She tells the story of how I was singing in the back car seat as a little girl, and she saw that I had talent.  We wrote our first song together when I was four.
  How did you land a job on Michael Jackson's This Is It tour?
  I did a small gig in Los Angeles and became friends with some musicians there.  One of them knew Michael's musical director and he invited me to audition. I did a small audition at the vocal director's house and a couple weeks later I was hired.  I remember them telling me, "Michael is on your Myspace page.  Change the picture!"  At the time, I was also hired to work at a clothing shop, so I quit that job and joined the This Is It tour.
  He was a master of stagecraft - what tips did he give you?
  Michael was fascinating to watch.  Working with him taught me the importance of seizing every moment on stage.  He painted pictures with every lyric and movement in his body.
  What do you remember of the day he died?
  I was sitting at a restaurant when my phone started blowing up.  There were rumours of his death but I didn't believe it.  It wasn't until later that day when this nightmare became a reality as I arrived at the Staples Center for rehearsal.  It was a very tragic day.   They had already begun to collapse the stage and pack up the gear.  Just the night before we were rehearsingâ€¦ It was surreal.
  What was it like to sing at the memorial service?
  It was an overwhelming experience. I mean, that was the same stage we rehearsed with him [on] two weeks prior. But it was a beautiful service.
  You were eliminated from the US version of The Voice - what did that experience teach you?
  When I was on The Voice, I made discoveries about my vocal style.  No matter what the song was, I always managed to turn it into a soul song whether I wanted to or not.  I learned that at the heart of it, I'm a soul singer.  My roots run deep, starting from the early days of jamming with my parents on Sly and the Family Stone and Curtis Mayfield songs.
  What difference did 20 Feet From Stardom make to your career?
  20 Feet From Stardom was a special project that resonated with so many people.  We were honoured with an Oscar and Grammy and many wonderful opportunities have come my way because of it.   People were inspired by the stories in the film and they continue to follow my story to see what happens next.
  How much of a struggle was it to make the leap to solo artist?
  It's a very rough road - that 20 feet from being a backing singer to an artist is a long 20 feet! But what keeps me going is a passion for music. No matter what, it makes me happy to do it.
  What's the biggest difference between working as a backing vocalist and fronting your own material?
  Working as a backing singer is being a part of a group effort to give the artist what they need.  It's a fun community to be a part of.  Being a solo artist is a totally different experience.  There is more responsibility and pressure, yet it is very rewarding.  I love sitting in the driver's seat, directing everybody to achieve the sound I'm looking for.  There's nothing more fulfilling than making the sounds you hear in your head become a reality.
  Who's the most demanding artist you've sung for?
  The most demanding was Natalie Cole.  It was a short show, but she was very particular about how she wanted the vocals.  I have much respect for her.  She kept the singers on their toes!
  How did you end up working with Prince?
  I did an interview and was asked who is my dream collaborator.  I said "Prince!"  He saw the interview and personally reached out to me.  I remember receiving the unknown call on my cell phone and freaking out while I was talking to him.  I officially met him at his album listening party in Los Angeles.  Shortly after, he invited me to Paisley Park and that was beginning of the collaboration.
  He's got a wicked sense of humour... Has he ever caught you out with a prank?
  He once called me and I didn't recognize his voice because he pretended to be someone else.  He can do great impersonations.
  What did he contribute to your album?
  He's a fantastic producer and arranger.  He played many instruments, sang, arranged, and even wrote.  He was very involved in the process, yet it was a great collaboration between his ideas and my ideas.  Most of the songs were already written and he helped me come up with great grooves and effective edits.
  Why did you call it Back In Time?
  I wanted people to feel like they have travelled back into a golden era of funk/soul music.  For me, personally, this record celebrates my childhood and upbringing in a musical family.  Many of the lyrics are autobiographical - describing where I came from, my old stomping grounds, and the amazing musical community that inspired me along the way.  The whole record feels like a dusty jam session in the basement of my parents' house.
  What song means the most to you?
  Angel In The Dark.  I think about the many times I felt like I was trapped in a dark tunnel, yet God has always managed to rescue me at the right time.  He is that Angel in the dark.
  Judith Hill's debut album Back In Time is out now on NPG Records.
target: You may not have heard of Judith Hill, but you've almost certainly heard her voice.