Haim topped the BBC's Sound of 2013 list last January, and went on to score a number one with their debut album, Days Are Gone.
Along the way, they got to play Glastonbury's Pyramid Stage, and serenaded Prime Minister David Cameron on an edition of The Andrew Marr Show.
The three 20-something sisters, from LA, got their start playing rock and roll covers with their mum and dad, in a band called Rockinhaim.
But their first album, Days Are Gone, won praise for its sleek harmonies, coruscating riffs and woozy 80s synth flourishes.
Ahead of the announcement of the Sound of 2014 next week, the band's youngest member, Alana Haim, reflects on the highs and lows of her first year in the spotlight.
Winning the Sound Of 2013 was crazy...
The day the list came out we were too scared to look at it, especially because there's a long line of us losing competitions. I think the only thing I've ever won was a spelling bee when I was in Second Grade, but I could be dreaming that, honestly.
So we didn't expect we were going to win. Then we got all these emails from our family and our manager saying we'd won and we were like "WHAT?!" We thought it was a joke.
No one came to see us at the South by Southwest (SXSW) Festival...
At the beginning of the week, we literally had three people at our show in this huge vineyard. It really felt like we were playing to no one. But we played over 10 shows and by the end of the week it was packed - you couldn't get in.
South By Southwest got a bad rep recently. People said no one got a break there any more. But by the end of the week, we had all these people buzzing about us, and it really helped with our EP. It was a South By Southwest story, like it used to be.
We got signed to Jay-Z's label in the US...
Jay-Z is a huge supporter and was really excited for us to be part of the company. We got to meet him, and he has the best laugh. What was he wearing? He was wearing a really nice suit. He looked pretty smart in his smart suit.
It took a bit longer than planned to finish the album...
There was this rumour that we were never going to put out a record but, personally, I didn't think we were taking that long. If we weren't proud of it, we couldn't put it out.
We used to say we'd scrapped three EPs of material but it's more like 10 at this point. We worked so hard and, on top of everything, on top of recording and mixing and mastering, we were on tour. It was the most stressful part of my life - but it was the most rewarding when we handed it in in July.
We got to play the main stage at Glastonbury...
Oh my gosh. I think Glastonbury is the one moment of my life where I am going to repeat the same story 'til I'm dead. I will never forget that weekend, ever in my life.
Everybody always talks about Glastonbury and I was like: "Yeeeah, whatever. I've been to festivals before, it's probably the same thing". Then you get there and it's breathtaking how insane it is.
And the fact that our first Glastonbury we got to play the Pyramid Stage? I don't know what they were thinking. It's the biggest honour for them to trust us enough to do that. That whole weekend is like someone roofied me and I'm making up all these stories. It doesn't seem real.
But my sister nearly died on stage...
We've been a band for six years and Este has never had a problem with her diabetes on stage. And of course it happened for the first time on the Pyramid Stage on Glastonbury.
I was terrified. A lot of people couldn't see but her face literally went white and I was, like, holy crap.
I thought she was crying, and she was taken aback with the emotion. I was like, "I'm down with it too, let's cry together' and she was like, 'no, I'm crying because I'm about to die".
But she totally championed it and kept going, and chugged orange juice and she was fine.
Hopefully if they invite us back again, they'll let us play the Pyramid Stage and we won't die. That's our next goal. Instead of a cool rock star rider, with lots of vodka backstage, we'll have endless amounts of orange juice and loads of candy.
Our album beat Justin Timberlake to number one...
That was really crazy because we're huge Justin Timberlake fans. Every girl is a huge Justin Timberlake fan. He's the biggest babe of the century. I grew up wanting to marry him.
People were saying to us, "how are you going to beat Justin Timberlake?" and I was like, "I don't want to beat him. I love him. But I kind of want to beat him. But I also want to be his best friend. I don't know what to do!"
I can't say that my parents didn't buy over 20 copies. But my parents were always going to buy 20 copies regardless of Justin Timberlake, because they wanted to give them out as Christmas gifts.
David Cameron said he liked our band...
We didn't know we were playing to the prime minister. We didn't even know what the Andrew Marr Show was!
They were filming it in Manchester because there was a conference there and we showed up to this weird office building. It felt like I was playing cover versions at my mum's real estate office for their Christmas party. And then they were, like, "and here's the prime minister" and we were like, "Woah! That guy's here!"
We really had no idea what was going on, but he was quite nice.
Playing Saturday Night Live was a big accomplishment...
SNL separates the men from the giants. If you're bad on SNL, everyone knows. It's weird because it's a comedy show - but it's got this crazy reputation for music. We had a longer soundcheck than anyone else has ever had because we couldn't get the sound right. We were apologising to everyone, but they kept saying, "We're fine. We love that you guys are so into it."
I hope they have us back. I'd love to be the first band to host.
We don't want to give back our Sound Of award...
I wish we were the Sound Of 2014. Just keep giving it to us. Come on, guys. What do we have to do?
The top five of the BBC Sound Of 2014 will be unveiled on the BBC News Website from 6-10 January, 2014.