Image copyright Getty Images Image caption Ed Sheeran, Lil Nas X and Camila Cabello can all lay claim to the song of the summer

Summer isn't officially over until 23 September, but as the nights draw in and the temperature drops, it's time to consider who had the season's top song.

Depending on who you believe, the title could go one of three ways.

Spotify says Ed Sheeran and Justin Bieber's I Don't Care was the UK's most-played song this summer.

On YouTube, though, the duo were beaten by Lil Nas X's Old Town Road, while Shazam's chart was topped by Shawn Mendes and Camila Cabello's Señorita.

For a decisive verdict, we need the Official Charts Company - who combine sales and streaming figures to come up with a definitive placings for summer's biggest songs.

And the winner is...

...Justin and Ed's I Don't Care, which came out on top with the equivalent of 755,000 sales, made up of 90 million streams and 115,000 downloads.

Like the best summer songs, it doesn't take itself too seriously - the video sees the two A-listers dressing up as ice creams and bananas as they sing about escaping a boring party with their girlfriends.

Musically, the song is built around the Tresillo, or Dembow, rhythm - a syncopated beat that's become a mainstay of summer songs, from Luis Fonsi's Despacito to Sheeran's own Shape of You.

Originating in Africa, the boom-ti-boom-chk rhythm made its way to Cuba in the 19th Century, where it became the basis for Habenera music.

After ricocheting around the Caribbean, the beat was co-opted into reggaeton, which has, in turn, inspired dozens of pop hits, thanks to its ability to evoke end-of-term excitement and long, hazy days in the sun.

On Spotify's global chart, where Latin music has a major presence, Tresillo underpins six of the summer's most-streamed songs, including Bad Bunny's Callaita and Daddy Yankee's Con Calma.

But there's more to the holiday season than having fun...

Lewis Capaldi's Someone You Loved soundtracked enough break-ups to become the UK's third most popular song of July and August (the singer's equally sorrowful Hold Me While You Wait came eighth, which tells you something about the fate of summer romances).

Billie Eilish's Bad Guy, on the other hand, couldn't be more moody, but crept into the top five by the simple trick of sounding like nothing else on the radio.

The same could be said for Lil Nas X, whose attempt to pull off a country-rap crossover was more successful than anyone could have imagined.

His breakout track Old Town Road, which topped the US charts for a record-breaking 19 weeks, was the UK's second-biggest song of the summer, scoring 723,000 chart sales.

It was also the UK's most-streamed video, topping the YouTube chart thanks to a hilarious, self-aware mini-movie that amassed 41.5 million views over the last two months.

Shawn Mendes and Camila Cabello's steamy duet Señorita also fared well on YouTube - amassing 23 million views to become the summer's second most-watched music video.

That, combined with the song's popularity on Shazam (which allows users to tag songs on their phone and add them to their music library), suggests it could have become the overall song of the summer, had it been released earlier in the year.

Señorita first hit streaming services on 21 June, several weeks after its closest competitors.

For all the real chart nerds, here are the various top 10s, as supplied to the BBC, in full:

Official Charts - Songs of the summer Artist Title 1) Ed Sheeran and Justin Bieber I Don't Care 2) Lil Nas X Old Town Road 3) Lewis Capaldi Someone You Loved 4) Shawn Mendes and Camila Cabello Señorita 5) Billie Eilish Bad Guy 6) Ed Sheeran ft Khalid Beautiful People 7) Stormzy Vossi Bop 8) Lewis Capaldi Hold Me While You Wait 9) Ed Sheeran, Chance & PnB Rock Cross Me 10) AJ Tracey Ladbroke Grove

Spotify (UK) Artist Title 1) Ed Sheeran and Justin Bieber I Don't Care 2) Shawn Mendes and Camila Cabello Señorita 3) Lewis Capaldi Someone You Loved 4) Stormzy Vossi Bop 5) Ed Sheeran ft Khalid Beautiful People 6) Billie Eilish Bad Guy 7) Ed Sheeran, Chance & PnB Rock Cross Me 8) Lil Nas X ft Billy Ray Cyrus Old Town Road - Remix 9) Lewis Capaldi Hold Me While You Wait 10) Meduza ft Goodboys Piece Of Your Heart

Spotify (Global) Artist Title 1) Shawn Mendes and Camila Cabello Señorita 2) Ed Sheeran and Justin Bieber I Don't Care 3) Billie Eilish Bad Guy 4) Lil Nas X ft Billy Ray Cyrus Old Town Road - Remix 5) Bad Bunny and Tainy Callaita 6) Ed Sheeran ft Khalid Beautiful People 7) Sech ft Darell Otro Trago 8) Lewis Capaldi Someone You Loved 9) Post Malone ft Young Thug Goodbyes 10) Post Malone ft Swae Lee Sunflower

YouTube (UK) Artist Title Views 1) Lil Nas X Old Town Road 41.5m 2) Shawn Mendes and Camila Cabello Señorita 23m 3) Ed Sheeran and Justin Bieber I Don't Care 21.8m 4) Lewis Capaldi Someone You Loved 20m 5) Stormzy Vossi Bop 19m 6) Billie Eilish Bad Guy 17m 7) Dave ft Burna Boy Location 13m 8) Mist ft Fredo So High 12m 9) Lady Gaga and Bradley Cooper Shallow 11m 10) Lewis Capaldi Hold Me While You Wait 10m

Amazon Music (UK) Artist Title 1) Ed Sheeran and Justin Bieber I Don't Care 2) Shawn Mendes and Camila Cabello Señorita 3) Lil Nas X ft Billy Ray Cyrus Old Town Road - Remix 4) Lewis Capaldi Someone You Loved 5) Ed Sheeran ft Khalid Beautiful People 6) Lewis Capaldi Hold Me While You Wait 7) Kygo and Whitney Houston Higher Love 8) Billie Eilish Bad Guy 9) Sigala and Becky Hill Wish You Well 10) Mabel Mad Love

Shazam (UK) Artist Title 1) Shawn Mendes and Camila Cabello Señorita 2) Joel Corry Sorry 3) AJ Tracey Ladbroke Grove 4) Kygo and Whitney Houston Higher Love 5) Dominic Fike Three Nights 6) Mist ft Fredo So High 7) Ed Sheeran ft Khalid Beautiful People 8) Young T and Bugsey ft. Aitch Strike A Pose 9) Freya Ridings Castles 10) Lewis Capaldi Hold Me While You Wait

Shazam (Global) Artist Title 1) Shawn Mendes and Camila Cabello Señorita 2) Billie Eilish Bad Guy 3) Meduza ft Goodboys Piece Of Your Heart 4) Lewis Capaldi Someone You Loved 5) Ed Sheeran and Justin Bieber I Don't Care 6) Lil Nas X ft Billy Ray Cyrus Old Town Road - Remix 7) Pedro Capó and Farruko Calma (Remix) 8) DJ Snake, J Balvin and Tyga Loco Contigo 9) Lil Nas X Old Town Road 10) Daddy Yankee ft Snow Con Calma

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