The 'Holding Onto Heaven' hitmaker, real name Louisa Rose Allen, is a huge fan of the 'Happy' singer and still can't believe he personally asked for her to be his support act on his European tour.
She told the Daily Star newspaper: ''I couldn't quite believe he knew who I was. He said he was a really big fan, he loved my sound and that I was really unique. I did this cover of his song 'Happy' and we chatted about that. He made me feel really comfortable, he's so chilled.
''I remember being a kid and just looking up to him and thinking he's just the king of music.''
It's a big year for the 25-year-old star, who will make her acting debut in an episode of the upcoming eighth series of the hit BBC sci-fi drama 'Doctor Who' but she admitted she initially had some reservations.
She explained: ''It's more singing than acting. That's why I'm doing it. Acting isn't something I thought I would get into.'
Here are all the performances from the comeback series of 'Twin Peaks'.
He's embarking on his first ever solo arena tour.
The singer has donated half a million to relief efforts.
Pratchett died aged 66 in March 2015.