When “California Gurls,” Katy Perry’s sugary, rollicking piece of pop, was unleashed in the summer of 2010 — out of car stereos, on TV commercials, at bars, barbecues and in the innuendo-leaden music video — it was like being steamrolled. The song, whether liked, loved or bemoaned, commands surrender — throw your hands up in defeat, give in to the fantasy; the lyrics “sun-kissed skin so hot we’ll melt your popsicle” have been woven into the pop cultural lexicon.

Perry’s song is one in a series of what the music industry and press calls Songs of Summer; the top 40 summer season hit that become so large, so beyond the scope of a four minute song that they permanently become part of the cultural consciousness. They are not forgotten. They define years, moments and artists’ careers. They are so well-known and have melodies and lyrics so easily regurgitated, that to not know them is alienating. Millenials know them: The Black Eyed Peas’ “I Gotta Feeling” (2009), Rihanna’s “Umbrella” (2007), Nelly’s “Hot in Herre” (2002).

But how does a summer song embed itself so permanently into our brains? Because you commit them to memory, says David Allan, an assistant professor of marketing at St. Joseph’s University in Philadelphia who has worked in the radio industry for more than 20 years, including at Clear Channel Communications. Summer songs are often experienced in the background to some of our most memorable moments — the soundtrack to summer fun. These episodic or autobiographical memories, Allan says, are why Songs of Summer stick with you 20 years later.

THE RULES

So what has 2012 wrought? With Memorial Day just behind us, there are a handful of contenders, frontrunners and outliers. To narrow down our own search, we’ve adapted some industry standard rules:

• No ballads 
• Top 40 radio fare are what will be primarily considered — they have the marketing and airplay muscle to become serious earworms. But we’ve indulged other tastes. 
• Songs that have reached number one on the Billboard Hot 100 before Memorial Day are ineligible (sorry, Gotye).

Going forward, we will give weekly Song of Summer 2012 updates, looking closely at songs’ ubiquity (that “booming-out-the-car-stereo” quality), sales and Billboard chart positions and general buzz. 

THE FRONT RUNNERS

Carly Rae Jepsen, “Call Me Maybe”

Bieber and tween-teen-approved, this seemingly innocuous breeze is really more like a Canadian storm system — no use hiding, it’s everywhere.  

Usher, “Scream”

We like “Climax” better, but based on how aggressively successful this single has been, it’s foolish to discount “Scream”’s au courant club rush. 

Rihanna, “Where Have You Been”

There’s an exotic, pulsating undercurrent to Rihanna’s latest. It’s not a classic like “Umbrella,” but it’ll take hold just as well. 

Justin Bieber, “Boyfriend”

He raps! Or something. Bieber’s attempt at Justin Timberlake-ification is intriguing, possibly misguided, but formidable.

CONTENDERS 

Katy Perry, “Wide Awake”

Having dominated the Song of Summer market for the past few years, Perry is an immediate contender, regardless of the (slower) song. 

Rita Ora, “How We Do (Party)”

An homage to Notrious B.I.G.’s “Party and Bullshit,” this song is a four minute hook: Jay-Z’s latest protege is our pick for the Song of Summer’s dark horse. 

One Direction, “What Makes You Beautiful”

Even amidst other teen stars like Jepsen and Bieber, these Brits and their breakout single have staying power. Its guilty pleasure factor is ridiculous. 

Maroon 5, “Payphone”

This is the kind of shimmery, widescreen pop that was this group’s claim to fame. It’s smooth.

OUTLIERS AND INDIE JAMS

Tanlines, “All of Me”

Those droning vocals and rhythmic syncopation wash over you in a beach party montage kind of way. An alternate summer jam. 

Icona Pop, “I Love It”

If only these Swedes were more famous! This is the kind of anthemic, blow-your-roof-off blitz that would do well on Top 40 radio. You will still hear this at parties. 

Santigold, “The Keepers”

Compared to other songs on this list, Santigold’s latest single is mellower and much simpler. “Keepers” is a nice foil to summer songs’ heavy production.