David Bowie will be remembered as "somebody who redefined pop music", according to his biographer.
Paul Trynka interviewed hundreds of Bowie's friends and acquaintances - from ex-lovers to fellow musicians - to help him write Starman: David Bowie - The Definitive Biography in 2012.
In a Press Association interview following the singer's death, Mr Trynka said: "Bowie showed us you have to get outside your comfort zone.
"Most of us when we have a winning formula we stick with it, when he had a winning formula he'd change it.
"That alone is something momentous so he will be remembered not only as someone who redefined pop music but as a creative force who endured over several decades.
"He will be remembered amongst the greats but not just one of them, as a unique great."
In his biography, Mr Trynka who was editor of Mojo magazine when Bowie guest-edited in 2002, explored how the star transformed himself from David Jones from Brixton to the superstar David Bowie through musical shifts and his performing personas.
The music journalist said: "He was born on the same day as Elvis. Elvis was this creative explosion and then Elvis suddenly came to the end of his creativity and couldn't work out how to go any further. But Bowie was different.
"He made himself into a talented person - there were several different manifestations of David, so many David Bowies. He did recreate himself."
Bowie's ever-evolving image saw him as characters including Ziggy Stardust, Aladdin Sane and in films such as Labyrinth as Jareth the Goblin King.
Mr Trynka said the decade between Bowie's 23rd album Reality in 2003 and The Next Day in 2013 gave him time to be "a family man".
He added: "He walked Lexi (his daughter) to school every day - something he had missed with Duncan (his son), which was something he deeply regretted."
Bowie lived just long enough to receive the critical acclaim for his 25th and final album Blackstar, which was well-received after it was released on his 69th birthday two days before his death.
Mr Trynka said: "He made the album and people loved the album without knowing he was ill so he survived long enough for the reception of this - to know his last work was loved. That is really something quite special - he certainly deserved it."
Many have seen symbolism of death and goodbye in the seven-track record including a line in the song Lazarus, which opened with: "Look up here, I'm in heaven."
Asked if there were hidden messages in the album, Mr Trynka said: "David Bowie's lyrics were always enigmatic. You were always supposed to read a lot into them.
"There's a message that we are on Earth and we will go somewhere else. There certainly is a spiritual message and we can read it. Bowie loved his time on Earth but now the alien has gone back into space."
Mr Trynka added: "I would thank David Bowie on behalf of a generation. Creativity sparks other creative urges in people and that is something special for all of us. So he's gone but other people will make wonderful music and great art and that's a wonderful legacy to leave."