Jessie J and Adele used to sing with each other at school.
The 'Sweet Talker' singer and the 'Skyfall' hitmaker were in the same year together at the BRIT School for performing arts in Croydon, South London, and Jessie has revealed the teenage pals would spend their lunch breaks making music.
Talking to PEOPLE, Jessie said: "We were in the same year! We used to sing at lunchtime together. Obviously at that time we didn't realise that we'd both "eventually" have music out. But she's amazing. She was always that really bright energy at school."
The 26-year-old pop star is still friends with Adele - who has a two-year-old son, Angelo, with her partner Simon Konecki - and they talk to each other when they get the chance.
She added: "She's wicked, and every time I get a chance, I try and text her. But she's super busy ... Global superstar, mum - standard."
Jessie hopes she and Adele, 26, will recreate their school days singing sessions and record a duet together in the future.
The singer - who has been nominated for her first Grammy Award for Best Pop Duo/Group performance for 'Bang Bang', her collaboration with Ariana Grande and Nicki Minaj - said: "She's on my wish list. I would love to hear our voices together because we're so different vocally. We wouldn't do a classic pop song, though, but something deeper."

Ed Sheeran couldn't stop laughing at the Victoria's Secret fashion show after Ariana Grande told him she loves "big black balls".
The 'Thinking Out Loud' hitmaker has revealed the 21-year-old singer made the admission as the pair chatted during the event earlier this month as giant inflatable spheres fell around them.
The 23-year-old star - who performed on the runway alongside the 'Break Free' singer, Taylor Swift and Hozier during the star-studded show - was spotted in hysterics as he exchanged words with the brunette beauty.
Ed has now admitted he isn't sure if the former Disney star was aware she had made an innuendo with her comical comment.
In an interview with Z100, he said: "Can I tell you why I was laughing? Basically there were all these big inflatable bouncy black balls that are bouncing around in the crowd on the finale bit.
"Ariana Grande comes up and stands up next to me and just looks at me and goes, 'I love big black balls.'
"I just burst out laughing, because in my head I was like, 'If she knows what that means then I love her, and if she doesn't know what that means, it's even better.' "
Ed also confessed to feeling small like "a hobbit" as the Victoria's Secret beauties strutted their stuff down the runway at the Earls Court Exhibition Centre in London earlier this month, and explained the gleeful look on his face during the performance was simply because he was "happy" to be surrounded by the stunners.
The 'Don't' singer - who is dating Athina Andrelos - explained: "It's just pictures of me being happy. I was there to do my job as much as everyone else was there to do their job...
"It was fun, but I kind of felt like The Hobbit in the Elvin Kingdom because everyone was [so tall]."

Kathy Griffin intends to "let people have it" when she takes over from the late Joan Rivers on 'Fashion Police'.
The 54-year-old comedienne has admitted she has some "very, very large shoes to fill" when she replaces the 81-year-old star - who died in September while undergoing a minor throat procedure - but is determined to adopt the former presenter's no-nonsense attitude when it comes to her comments.
Speaking on 'Jimmy Kimmel Live!', she said: "In her honour, I will not be holding back. I am giving no passes, I am going to let people have it, I'm gonna bring the hammer down.
"This was a job that was held by our dear friend Joan Rivers. I understand I have some very, very large shoes to fill."
Kathy then decided to practice her tough-love approach discussing the fashion choices of celebrities on the programme by testing out her tactics on Jimmy.
She told him: "You might want to up your game. I'm tired of the same suit every time. I get it. It's Gucci, it fits well - yawn!
"Give me some sparkle! Give me a fig leaf! Take a risk for god's sake. Don't just show up again looking nice-ish. Give me something."
Kathy will take over from Joan - who hosted the show since its first episode in September 2010 - on January 12, 2015 and will front 17 new episodes alongside fellow newcomer Brad Goreski and returning panellists Giuliana Rancic and Kelly Osbourne.

Benedict Cumberbatch has been nominated for two Screen Actors Guild (SAG) awards. The 38-year-old actor is in the running for honours in both the TV and movie categories, and will contest for Outstanding Performance by a Male Actor in a Television Mov...

Benedict Cumberbatch's two Screen Actors Guild (SAG) Award nominations are an "amazing early Christmas present".
The 38-year-old star - who's been nominated for Outstanding Male Actor in a Leading Role for 'The Imitation Game' and for the Outstanding Performance by a Male Actor in a Television Movie or Miniseries for 'Sherlock: His Last Vow' - is thrilled to be in line for the prestigious awards.
He shared: "I'm over the moon. And so delighted to receive recognition in such esteemed company for both 'Sherlock' and 'The Imitation Game' by my acting peers.
"What an amazing early Christmas present! Thank you to all who voted and watched both pieces of work."
Keira Knightley, Benedict's co-star in 'The Imitation Game' has been nominated for the Outstanding Female Actor in a Supporting Role prize and is "honoured" to be up for both that award - which she will contest with Meryl Streep, Patricia Arquette, Emma Stone and Naomi Watts - and Outstanding Performance by a Cast in a Motion Picture with her castmates.
She said: "Thank you so much to the Screen Actors Guild. It's such an honour to be nominated by your peers and in the company of this group of talented women. I'm thrilled to celebrate this morning with Benedict Cumberbatch and the cast."
Elsewhere, Hollywood superstar Jennifer Aniston has been nominated for the Outstanding Female Actor in a Leading Role award for her performance in 'Cake', in which she plays a woman who manages her chronic pain with illegal drugs and feels "blessed" to have gained recognition.
The 45-year-old actress said: "This is the best 6:00am wake up call ever.
"Words can't describe how blessed I feel to be recognised like this by my peers for this film. What an enormous feeling of joy and gratitude."
The SAG Awards will be held on January 25, 2015 in Los Angeles.

Amy Poehler writes topless as a "treat" to herself.
The 'Parks and Recreation' actress finds it relaxing to work while partially nude and kept herself motivated when penning new memoir 'Yes, Please' by allowing herself to strip as she wrote.
She said: "I find that writing topless relaxes me.
"I think it was probably accidental, like I was out of the shower and I was like, 'I have to finish this thing' and then I was like, 'This feels really good.'
"And then as I was writing the book, as you know when you're writing a book, you're like anything to get you inspired to write. As a treat to myself - I'd be like do this one topless."
In her book, the 43-year-old actress - who has two sons, six-year-old Archie and four-year-old Abel with former husband Will Arnett - admitted she is a snoop who can't resist rummaging through people's possessions and she is unapologetic about her actions.
Quizzed on the subject by Ellen De Generes, she said: "I do. Yeah. I will look through all your stuff if I go in your house. Period. End of sentence."

Monaco's Princess Charlene has given birth to twins.
The 36-year-old royal and her husband Prince Albert welcomed a baby boy and a girl into the world this morning (10.12.14) after she was admitted to the Princesse Grace hospital in the principality, where she is thought to have given birth via caesarian section.
Local newspaper Monaco Matin first reported the news but it is not known whether 56-year-old Albert was by the South African-born beauty's side or not during the birth.
The little boy will automatically be the heir to the throne regardless of whether he was the first born of the two or not.
The births have not been officially announced by the Palais Princier yet but when they are then they will be recognized by 42 cannon shots - double that of a single royal baby's birth.
Charlene announced she was pregnant in May and the former Olympic swimmer recently confirmed she was expecting twins and feeling fantastic about her pregnancy.
She said: "I feel absolutely great."
In October, New York plastic surgeon Dr. Jon Turk revealed Albert had been working hard to childproof the royal couple's home ahead of their impending new arrivals, and he was particularly concerned about the sharp edges on the tables.
He explained: "The princess told me that he's been walking around their residence and their summer house, starting to childproof the houses.
"He's worried about the corners of tables. And she's saying they're not even born yet! He's also going to put air in all the balls for soccer and basketball. He's already getting ready and it's still years away before they can play with a ball."

Britain's Prince William encourages Prince George to play on his iPad.
The 32-year-old royal - who is expecting his second child with his wife Catherine, Duchess of Cambridge, also 32 - revealed how his 16-month-old first born loves exploring the games available on his dad's tablet.
At the GREAT Tech Awards in New York last night (09.12.14) CEO of children's toy company littleBits, Ayah Bdeir explained how the father-of-one had been open about his desire for his offspring to get involved in technology.
She told the Daily Mirror newspaper: "He told me that his son George has been playing iPad games and loves them, and that this was a good way to teach him the inner working of electronics."
Held at the iconic Empire State Building, Prince William and the Mayor of New York handed out the winners of the 2014 GREAT Tech Awards, which honours technology entrepreneurs from the United States of America and the United Kingdom.
Mayor Bill de Blasio - whose wife, Chirlane McCray accompanied the Duchess to a children's charity on Monday (08.12.14) - has praised his citizens for embracing the royals during their three-day stay.
He told the crowd: "The warmth and energy make me proud of my city."

Ben Haenow wants to make his mother's life easier by winning 'The X Factor'.
The 29-year-old singer - who will compete against Fleur East and Andrea Faustini in the final of the ITV competition this weekend - confessed he would love to take the top spot so he can look after his mum and family in the future.
He told MailOnline: "It would make my life!
"It would help get us, my family, in a better place. We live in a council estate and me, my mum and brother live together. So I'd like to sort my family out with somewhere else to live.
"I just want to make my mum's life a bit easier. I'd like it if she didn't have to worry as she gets older and for her not to have to work quite so hard."
London-born Ben added he was close to giving up on his music career before trying out for the show as the criticism started to get to him.
He said: "For me, it's about trying to succeed in an industry that for I've been trying to making it in for years, to the point of nearly giving up.
"We used to play gigs around the South East. When you're spending money on petrol and not being paid anything to cover costs, it becomes hard slog.
"I started thinking, 'I'm playing to five or ten people and I've travelled all this way. What for?' People are just there to drink - not really to listen to your band anyway."

Stevi Ritchie thinks Ben Haenow will win 'The X Factor'.
The 34-year-old wannabe popstar has revealed he'd like to see his fellow over 25 contestant win the competition after being voted out last month.
He said: "To be honest I have to go with my overs. Ben or Fleur, I think possibly Ben might win it, but a lot of people are saying Fleur ... I mean all three of them are going to get record contracts without a doubt, but I think Ben has probably got the edge. I don't know why but I think he'll clinch it."
The cheeky chappy also confessed he wishes he'd made it to the final this weekend so he could've performed a duet with his musical idol.
Quizzed on what song he would've sung in the final, he said in a Q&A with Mecca Bingo: "Straight forward, Olly Murs as my celebrity duet and singing 'Dance With Me Tonight', definitely. I think that would be a great one because it is the first audition that I did, and of course I forgot the lyrics, so it would be quite ironic to actually remember the lyrics and do it with Olly. [sic]"
Meanwhile, Stevi is hoping his former mentor Simon Cowell will offer him a presenting gig in the new year.
He added: "Well I would still like to say that I will keep in touch with Simon and he will offer me a job next year, doing something on camera, I don't know what, anything really."

Steven Moffat is glad people have accepted Peter Capaldi as Doctor Who.
The BBC One sci-fi series' showrunner has confessed he's looking forward to developing the character now audiences have gotten used to the 56-year-old actor playing the role previously portrayed by stars including Tom Baker and Matt Smith.
Speaking about making the last series, in which Capaldi made his debut as the titular Time Lord, he said: "I was looking for the Capaldi moments every episode, saying, 'We need a Capaldi moment, that moment where he's not Matt Smith, he's not David Tennant, where he's a dangerous, unpredictable, volatile character."
The 53-year-old writer and producer claims he had to work so hard to distinguish Capaldi as a character because otherwise viewers would have become complacent.
He continued: "The longer you do a show the cosier it gets, the cosier it gets the nearer to death it gets. You really have to say to people, 'Pay attention. He's far more unpredictable that that'.
"So now, having done that, and having blasted our new Doctor at them, we can go other places with him. We don't have to work at that anymore because people just accept him."
And Steven is now excited about being able to focus entirely on the storyline in the next series.
He added to SFX magazine: "I won't be looking for the Capaldi moment next year because the whole show is a Capaldi moment."

Bjorn Ulvaeus says ABBA will never return to the stage.
The 69-year-old singer-songwriter was a member of the hit band - along with Agnetha Faltskog, Benny Andersson and Anni-Frid Lyngstad - until their hiatus in 1982, and has repeated previous remarks confirming they will never reform.
He said: "We took a break in `82, and it was meant to be a break. It's still a break and will remain so,
"You'll never see us onstage again."
The 'Dancing Queen' hitmaker continued to say the group has no reason to reform because they are not strapped for cash, unlike other acts who decide to tour because they have been reckless with their money.
He continued: "We don't need the money, for one thing,
"Usually the reason bands have reunions is that one of them is destitute and the others want to help. Fortunately that has not happened to us."
The 'Mamma Mia' creator was speaking about the band following the release of 'ABBA: The Official Photo Book' which chronicles the Swedish group's decade-long career with more than 600 photographs, and admitted he enjoyed taking a look back through their history, despite not wanting to regroup.
He told Billboard magazine: "I'm not a nostalgic person, but looking at these pictures really took me back."