It's Tuesday! Time for another round of "5 Must-Hear Pop Songs of the Week!"

This week's roundup features not one, but two rising U.K. girl groups, a former U.K. girl grouper-gone-solo, a Disney starlet about to break out in the music scene, and, of course, the Lover of Love Songs (and birthday girl) herself.

1.) Selena Gomez, "Stars Dance"

'Tis a holy week for Selenators around the world: Not only did Selena Gomez (birth name Selegendary Gomezmerizing, in case there was any confusion) just celebrate her 21st birthday with her entire crew, but she finally released her brand new record, Stars Dance, today! The album's full of storming EDM-inspired uptempos, but one of the best offerings is the title track, which sees the "Love You Like A Love Song" chanteuse floating along spacey electronica, dubstep grinds, and dramatic strings: "I can make the stars dance if you want me to," she purrs. It's one of Selena's most confident -- dare I say, sexiest -- tracks to date. Light up the moon!

+ LISTEN TO SELENA GOMEZ, "STARS DANCE"

Listen to more Must-Hear Pop Songs after the jump.

2.) M.O, "Hot"

Up-and-coming U.K. R&B-pop trio M.O (featuring Frankee from the gone-too-soon electro-pop duo, Mini Viva) have slowly been making waves across the pond with their breezy throwback releases, including "Wait Your Turn" and "Ain't' Got Time" -- and they're not stopping. The girls are back this summer with "Hot," a... well, hot new track: "When you played with her, you murdered us both/ I knew that you were, but you lied under oath," the girls croon. With its catchy, understated chant ("You think you're so ha-ha-ha-ha-ha-hot!") and smooth reggae flow, it's hot enough to melt your popsicle. (Right, Katy?)

+ LISTEN TO M.O, "HOT"

3.) Little Nikki, "Little Nikki Says"

You might not know Little Nikki just yet, but by the time you hear her blazing debut, "Little Nikki Says," you'll be following orders in no time. The London-based 17-year-old songstress, formerly of short-lived U.K. girl group SoundGirl, is going the solo route in September with the confidently titled track, "Little Nikki Says." The thumping electro-dancehall number sees the singer entering the club and delivering orders "Simon Says"-style: "Little Nikki says put your hands up high, Little Nikki says take your hips down low/ Stop! Nikki didn't say," she declares, leading to an utterly nasty beat breakdown that'll have you doing unholy things to the air. Not since the "Cha Cha Slide" has an instructional dance track been so much fun.

+ LISTEN TO LITTLE NIKKI, "LITTLE NIKKI SAYS"

4.) Neon Jungle, "Trouble"

The U.K. girl group takeover continues! While M.O's serving up a slice of throwback '90s R&B, the feisty foursome known as Neon Jungle's bursting onto the scene this fall with fists held high on their rallying electro-pop cry, "Trouble": "I don't look for trouble, but trouble looks for me!" the girls declare above the slamming debut track, which recalls the rowdiness of early Girls Aloud. If the accompanying video's anything to go by -- the girls tear up a house and go positively nuts o'clock -- I'm pretty sure they're the ones causing the ruckus. Regardless, it's definitely the kind of trouble I'd like to get into.

+ LISTEN TO NEON JUNGLE, "TROUBLE"

5.) Zendaya, "Replay (Belanger Remix)"

Zendaya's already a Disney superstar, and now she's about to come for all sorts of wigs as a singing sensation. The 16-year-old "Dancing With The Stars" finalist (she came in second place a few months ago!) just premiered her ah-mazing debut, "Replay," which we've all been loving. Now, along with the track's premiere, Princess Z's just unleashed a slew of remixes for the club. The Belanger mix gives the minimal original a healthy dose of hypnotic synthesizers and delicious vocal stutters, making "Replay" -- you guessed it -- even more replay-friendly. Put this one on all day. Eh-eh-everywhere you go!

+ LISTEN TO ZENDAYA, "REPLAY (BELANGER REMIX)"

Bradley Stern is a writer from New York. In his spare time, he enjoys organizing his Britney Spears CD collection in reverse chronological order and writing impassioned letters to Congress urging that Madonnalogy be taught in all public schools. But most of all, he spends his time tweeting and musing daily about pop music on his blog, MuuMuse.

Photo credit: Getty Images / Little Nikki / M.O / Neon Jungle