Image copyright Getty Images Image caption Dua Lipa, George Ezra and Cardi B are all contenders for the song of the summer

Music sounds better in the sunshine. There's no scientific evidence for that, but it's a fact.

And with the UK in the middle of a heatwave, it's time to indulge in one of music's purest pleasures - the summer song.

Whether it's frothy and euphoric or laid-back and relaxed, every year produces one song that defines the season.

Last year, it was Luis Fonsi's Despacito. The year before it was Drake's One Dance. But who will take the crown in 2018?

We asked some of BBC Music's experts to select the song that's soundtracking their barbecues, pool parties and road trips.

George Ezra - Shotgun

Mark Savage, BBC Music reporter: What better way to soundtrack the summer than a song about a road trip to the beach? George Ezra's bouncy, carefree Shotgun has lyrics about "bikini bottoms and lager tops" and, for bonus sunbeams, resurrects the fretless bass sound of Paul Simon's Graceland. It's already number one, and it looks set to stay there. (But if not, I'll nominate Tiesto and Post Malone's delightfully daft Jackie Chan as an alternative.)

Lizzo - Boys

Lauren Brennan, music producer at BBC 6 Music: Detroit-born/Houston-raised Melissa Viviane Jefferson, AKA Lizzo, recently dropped this sassy new banger that's been funking up the 6 Music playlist. That she shares a first name with Missy Elliott comes as no surprise - she rivals the rap icon for attitude and energy. Newly signed to Atlantic, expect new music across this year.

Cardi B, Bad Bunny and J Balvin - I Like It

Sarah Beaumont, co-music lead, BBC 1Xtra: This Latin and Caribbean infused track has a well-known sample, which gives it an instant sense of familiarity. 2018 really has been Cardi B's year and she's teamed up with two of reggaeton's biggest stars, making this a sure-fire summer hit. As soon as I hear this I'm transported to the beach with a cocktail in hand!

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Chaka Khan - Like Sugar

Kevin Geoghegan, BBC Music News Live: Anyone who can't find it in themselves to even do the tiniest desk shimmy to this song is dead inside. There are some (reasonable) complaints that Chaka doesn't feature heavily enough in the track but her small but perfectly-formed contributions are unmistakable.

Calvin Harris and Dua Lipa - One Kiss

Annabel Rackham, BBC Entertainment reporter: You can't go wrong when you combine the current biggest female pop act with one of the world's most successful DJs. The nostalgic, washed-out vibe is reminiscent of 90s dance music, but it also has the commercial appeal, which means it can be played everywhere. Combine that with the eight weeks it spent at number one and you've got a solid case for it being song of the summer.

Arctic Monkeys - Four Out Of Five

Jimmy Blake, Music reporter, Newsbeat: Some people initially weren't on board with Alex Turner taking up piano for their sixth album - but a hearty Scottish sing-a-long of this track at the Monkeys' set at last week's TRNSMT festival suggests fans have accepted the gear shift. The track might not scream "Pimms o'clock in a beer garden" but, for some of us, it will forever soundtrack summer memories of the Arctics crooning their way back to headliner status after five years away.

Courtney Barnett - City Looks Pretty

Paul Glynn, BBC Music News Live: OK, this song is ultimately about "a dismal day" but it's testament to the power of a sunny one - as the Aussie slacker shakes herself out of a depressed indoors funk by enjoying the simple pleasures of a stroll around Melbourne. For those on wheels - not foot, like Courtney - the killer distorted guitar riffs will help fuel your summer spin, while a cool, slow-tempo musical breakdown halfway through may encourage you to pull over to the left-hand lane and enjoy.

Send us your suggestions for the song of the summer on Facebook, on Twitter @BBCNewsEnts, or by emailing entertainment.news@bbc.co.uk.