Summer is less than a week old, but guesses are already in for what will be the so-called song of the summer.
Streaming services Spotify and Pandora have put out their picks, based on user data . Both lists include the Justin Bieber remix of the Luis Fonsi-Daddy Yankee tune Despacito and Selena Gomez's Talking Heads-sampling Bad Liar.
A lot goes into crafting these tunes — choosing the right collaborators, picking a proper melody, deciding how fast or slow the tempo will be, even timing when it should be released.
And though the musicians you know — Bieber, Miley Cyrus, The Weeknd — play a part, it's their lesser known co-songwriters who help ensure they have a hit.
Here are some musings about what makes a good summer song and advice on how to craft one from those who have helped write some of the biggest hits of the past summers.
Moccio, a pianist-composer who grew up in St. Catharines, Ont., was a co-writer on Miley Cyrus' late-summer 2013 hit Wrecking Ball and has written for The Weeknd, Celine Dion and Sarah Brightman.
You can't predict a summer hit: "I have to use Wrecking Ball. That day I didn't want to write a song and I came out and I ended up writing one of the biggest songs of that year.
'It wants to be high energy enough to dance to and chill enough to hang out to.' - Scott Harris, co-writer for Shawn Mendes, on what makes a good summer song (CBC interview)
And that's how it often works for me. When I'm not thinking about it, my guard's down and then I [boom], I hit the grand slam."
Breaking down what works: "We know that 60 beats per minute (BPM) works. We know that 64 BPMs works … we all clock these because our hearts beat at specific rhythms so if you try to generalize the way that, you know, the cortex of the brain goes with the heart, you could come up with a formula."
Wilcox is a songwriter who was born in Hamilton and now lives in Los Angeles. She has co-written for Britney Spears, Fifth Harmony and Josh Groban, but her biggest hit was another late summer smash — Nick Jonas's 2014 song Jealous.
Some summer hits are timed: "The label will say, 'We're going to release this in the fall, because we think it'll do well over the Christmas holidays' or 'We think this is a summer song, so we're going to build it up so it hits Europe in July.'"
'It's got to be island flavour. It's always got to be a dance hall-reggae thing. It's got to remind you of the beach.' - Montreal musician Karl Wolf on what makes a good summer song (CBC interview)
Labels are conscious that summer is opposite in the southern hemisphere. They may roll out songs later in the northern hemisphere's summer — like Jealous and Wrecking Ball — so they can still be considered songs of the summer when summer hits the south.
Good summer songs use new ideas: "Every person I work with … wants to move the needle and do something new and is always striving to break the mould. Not to just create something that's cookie cutter. And I just think it's important to note that when you go into the studio to write your song, you should be trying to move the needle."
Frank is a DJ-songwriter who grew up in Vancouver and now lives in Toronto and Los Angeles. He wrote last summer's hit Closer with The Chainsmokers. Its lyric video has more than 1.6 billion views on YouTube.
Summer song needs to sound different: "I think it has to be somewhat unique, something about it — whether it's lyrically or melodically or how it sounds — has to have some unique thing to it so it attracts people on a mass scale first." Frank gave the example of Gotye's summer 2011 song Somebody That I Used to Know.
'I think that's a dangerous game, you know? We've never created a song trying to make it sound like summer.' - Imagine Dragons' frontman Dan Reynolds (CBC interview)
'No science to a hit song': "When you are writing for someone else, I think it is important to have a sense of understanding who that person is, 'cause I feel like the most successful songs are the most honest songs so best to write it with that person." Frank added it is more likely to be a hit if it is relatable to a lot of people.
Messinger — who grew up in Toronto but lives in Los Angeles — had one of the biggest hits of summer 2014 with Magic!'s Rude, which he co-wrote and produced. It was released during the southern hemisphere's summer and went big in the northern hemisphere when summer came around. Messinger has also written for Bieber, Shakira and Pitbull.
It can be cookie cutter: "Sometimes there are targets that get pretty specific when writing sessions start."
'You want to walk into any situation or session … with a purpose, but you want to keep all the spontaneity and impulse in it as possible.'- Hedley frontman Jacob Hoggard on writing a hit song (CBC interview)
It doesn't have to sound summery: "The tempo might not instantly be something you would think is … a summer jam, but it might just have the patterns and the melodies that are so catchy, so digestible, that they just translate and connect with people in a way that could be the song of the summer as much as anything else."
Wilcox, Frank and Messinger all took part in a Facebook Live discussion on what goes into making a smash summer pop hit. Watch and share your thoughts on what will be the song of this summer on Facebook or the comments below.