"It worked with my chemo schedule, so that's why we were able to do Glastonbury."
Holly Wellington was diagnosed with breast cancer a year ago - but she's now got the all-clear.
The 26-year-old singer from electronic jazz group Ishmael Ensemble told Radio 1 Newsbeat music got her through a difficult period in life.
"I spent most of the time on the sofa or in hospital and had such little energy. But whenever I did, I'd put it into performing," she says.
Holly spoke with us from the Royal Albert Hall, where her band are playing a gig for Teenage Cancer Trust.
'It made me really anxious'
She credits her band-mates with Ishmael Ensemble for being so supportive.
"It was terrifying. Especially because I had two family members pass away as well."
"Everything changes. I thought I might not be able to commit to anything anymore, so it made me really anxious."
But the band gave her enough space and reassured her that they "would play together again".
"It really meant a lot to me, I've had so much support and kindness from them."
During her treatment, Ishmael Ensemble did around 40 gigs, many of which Holly managed to make - including Glastonbury last June.
The group worked out a solution where Holly didn't have to be performing every time. But if she was able to, she'd "jump in".
Holly says memories of Glastonbury are "a blur".
"We somehow got me in - and I just drove in and drove out."
At the time Holly had no hair, her white blood cells were really low and "she couldn't be around anyone" in case she picked up bugs.
To make it even more memorable, Holly's dad - who had never experienced Glastonbury before - came along and watched her.
"My dad was having the best time."
Holly spoke about her condition on stage and got a lot of love from the audience - which made it more special.
The music world and the medical world has collided throughout for Holly during the past year.
"I remember going to the hospital after having played at a jazz cafe the night before. So I had a wristband on - both the cafe and the hospital."
Holly made lots of friends around the world who were going through similar treatments.
"From Australia, America, they posted stuff on social media about their journey. We've become really close friends even though I've never met them.
"But we've all gone through this one thing that only we can understand."
'They've always been there for me'
Holly is thankful that the Teenage Cancer Trust has been there for her from the start and got her through tough moments.
"They sorted me out with psychologists in the hospital when the thought of starting chemo was terrifying."
She found it "really difficult" when she lost her eyebrows and eyelashes.
But the Trust "gave feel good sessions and gave a lesson on how to redo eyebrows and eyelashes".
And that's not all, they've also given the band the opportunity to play at the Teenage Cancer Trust gig.
"I am so excited to walk out and look around to see the majesty of it."
"I remember going on school trips every year to the Royal Albert Hall to see The Proms and stuff, and it was unreal."
'Give yourself time and space'
Holly says she's learned a lot from her journey.
"Be kind to myself and you've got to give yourself that time and space if you're feeling crappy."
She says that she's fortunate to do music, because it's something to put time and energy into.
"I've had some amazing writing sessions over the past few months. Hopefully we can create something beautiful that can make others feel good too."