For Top 40 radio, there’s a lot riding on the Summer Song of 2018 candidates. The mother/daughter coalition is beyond frayed. Tempo is negligible (I heard a major-market CHR segue this week from Post Malone, “Rockstar,” to Max, “Lights Down Low”). April PPM ratings were dismaying even for some stations that had withstood the format downturn. The format needs its moment in the sun.

So make it count, radio. As has been the case for the nearly 15 years that we’ve been writing about the summer song, this isn’t a listing of every likely summer hit. It’s songs with some degree of tempo or tropicality. Drake’s “Nice for What” is a hit, but it’s not his “One Dance”/”Passionfruit”-type entry. There are also at least 2-3 major titles likely to drop over the next 14 days. And at his current rate of productivity, an uptempo Drake song is probably on the way, too. But among the candidates so far:

Calvin Harris & Dua Lipa, “One Kiss” — Ever since naming a song “Summer,” he’s been a reliable entrant in the Summer Song derby. But at this time of homogeneity, Harris has also been surprising, going from “This Is What You Came For” to “Feels” to “One Kiss.” In the U.S., it’s top 15 already. In the U.K., it’s this week’s sales No. 1. And among Facebook friends who weighed in on the topic, it’s one of the most mentioned. (There were also votes for Lipa’s solo “I.D.G.A.F.”)

Ariana Grande, “No Tears Left to Cry” — A year ago, after the Manchester Arena bombing, I asked “what then do people need the Summer Song to be in 2017? Does it need to take on the weight of its surroundings? Or will it be a vessel through which people keep calm and carry on?” This month, Grande, whom I already admired immensely for returning to Manchester for the One Love concert, answered that question herself. “No Tears Left” is already top 10 and the No. 1 single in the U.K.

Selena Gomez, “Back to You” – This time a year ago, the Gomez-produced “13 Reasons Why” was propelling the unlikely “The Night We Met” by Lord Huron into pop culture (if not CHR radio). This year, its powers are being harnessed for Gomez’s own Summer Song entry, which goes into Memorial Day with a nearly 3,000-spin increase.

Backstreet Boys, “Don’t Go Breaking My Heart” – Summer has long been a vehicle for artist comebacks; now we’re at the comebacks-within-comebacks stage. Eight years ago, Pitbull powered Enrique Iglesias and Jennifer Lopez back to the forefront. Now, Iglesias and Pitbull are hoping to help each other on “Move to Miami,” while Lopez is going straight to DJ Khaled and Cardi B in her quest for “Dinero.”

On one hand, a Backstreet Boys comeback would be the wildest of them all. But late ‘90s gold from Backstreet, ‘N Sync, and Spice Girls have all re-emerged at AC radio to some degree since last summer. And when CHR is at a crossroads, PDs often embrace comebacks. There’s also room for BSB to reclaim a category they helped reinvent 20 years ago. Charlie Puth, “Done for Me”; BTS, “Fake Love,” and 5 Seconds of Summer, “Youngblood,” are pursuing the title, but Shawn Mendes went for something more sober, a year after “There’s Nothing Holding Me Back.”

Cardi B, “I Like It” – The success of “Despacito” last summer led to a boomlet of reggaetón crossovers during the fall. As this summer begins, many of the similarly flavored contenders are coming not from Latin radio, but bespoke collaborations such as the cleverly concocted Liam Payne/J. Balvin, “Familiar.” This one serves an additional purpose. As CHR continues to wrestle with acknowledging streaming-driven Hip-Hop superstars as more than featured artists on pop singles, it’s the most accessible record Cardi B  could have possibly provided. For several readers, the favorite of those songs not already confirmed hits.

Childish Gambino, “This Is America” – It’s not summer song frivolity; it is (among many other things) a comment on summer song frivolity. “This Is America” is a column unto itself, but it will be a phenomenon that takes place during the summer. Rich Appel writes, “The first time I heard/saw it, it reminded me of the first thing I heard in another near-song-of-summer, Edwin Starr’s ‘War.’”

There are a few titles already on the U.K. charts worth flagging. WILI New London’s Kevin Pilz mentions Anne Marie’s “2002,” also channeling nostalgia for that era. Years & Years’ “If You’re Over Me” draws from both their usual late-‘80s Euro-inspiration and the acoustic whimsy of the early 2010s.  And finally …

George Ezra, “Paradise” — Nothing seems more unlikely at this moment in CHR’s travails than finding an uptempo summer hit on the Triple-A chart. But “Feel It Still” was an unlikely crossover, too, until it wasn’t. So think of “Paradise” as the U.K. pop hit that just hasn’t come over here yet. And although he wrote this himself, if Ezra had deliberately teamed with Max Martin in search of the bubblegummiest possible version of what he does, would it not sound like this?

Tiesto & Dzeko f/Preme & Post Malone, “Jackie Chan” – I heard this for the first time about eight hours after this column was first posted. “If every Post Malone single or feature could have tempo like this, CHR’s issues would be over.” There was a rapid chorus of agreement. I’ll be writing about any songs that drop after Memorial Day in subsequent weeks, but this list felt incomplete without a late addition.

And now, your comments on the Summer Song of 2018 are welcome.