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

This week's round-up features a comeback track from an Aussie pop princess, the latest offering from a girl group across the pond, an unreleased demo from a living legend, a dazzling new dance tune from one of the best disco-pop troupes around.

1.) Delta Goodrem, "Sitting On Top Of The World"

Like all proper Australia pop stars (see also: Queen Kylie Minogue), Delta Goodrem is an incredibly successful, beautiful and talented singer-songwriter who got her start on the Aussie soap, Neighbours. Over the past decade she's made a killing down under, serving up three studio albums and an impressive 8 No. 1 singles.

Nearly four years after her last single, the gorgeous chanteuse has at long last returned with "Sitting On Top Of The World," a swoon-filled, carefree pop ditty about living life and loving life and living in love and all of those wonderful and amazing things that pop dreams are made of. "So get up, stand up/ What you waiting for?" she happily commands. I'm up! I'm up!

The video for the song is equally amazing (and/or alarmingly similar to what I see whenever I close my eyes), featuring Goodrem and a troupe of happy-go-lucky ladies and gents dancing around with balloons in hands. I want to go to there!

+ LISTEN TO DELTA GOODREM, "SITTING ON TOP OF THE WORLD"

Listen to more Must-Hear Pop Songs Of The Week after the jump!

2.) Scissor Sisters, "Only The Horses"

After getting their sassy strutting on with buzz single "Shady Love" featuring Azaelia Banks back in January, glam pop-rock outfit Scissor Sisters are back with their very own version of Rihanna's "We Found Love." Crafted by Scottish beat-master Calvin Harris, the lead single from their upcoming record Magic Hour features a sizzling Ibiza-ready beat breakdown and the most euphoric of choruses: "Only the horses can find us tonight!" the endlessly sexy Mr. Jake Shears cries out on repeat.

With its shimmering beats and lovely disco pulsations, "Horses" might just be the perfect happy medium between the troupe's dirty disco sound and the radio's current love affair with all things club-pop to give the Sisters their biggest hit yet. Saddle up!

+ LISTEN TO SCISSOR SISTERS, "ONLY THE HORSES"

3.) Britney Spears, "Money, Love & Happiness"

Way before Femme Fatale, Circus and even Blackout, there was a mysterious time in Queen Britney's career following 2003's In The Zone known amongst hardcore fans as the Original Doll era. 'Twas a time where my Queen was newly smitten by a background dancer named Kevin Federline, rapidly growing sick of the fame and fortune, and getting mighty rebellious in the recording booth. That album ultimately never came to be. However, one of the songwriters present during those sessions, Michelle Bell, just leaked one of the heavily rumored demos from those sessions last week: "Money, Love & Happiness."

Crooning on top of a gritty electronica beat produced by the then unknown RedOne (that's my girl, always the innovator/game changer!), Brit Brit lays down the law with cocky quips ("Don't take this out of context, but when it comes to being the best, there ain’t no contest”) and wishes to get away from it all: "A fairy land of dreams, that is where I'll find/ Everything I need to have a piece of mind," Britney yelps during the bridge.

For fellow fans of the Holy Spearit, this one's an invaluable glimpse into the life of our living legend right at the heart of her rebellion.

+ LISTEN TO BRITNEY SPEARS, "MONEY, LOVE & HAPPINESS"

4.) The Saturdays, "30 Days"

Time goes by so slowly, as a famous woman in a spandex leotard once sang. And judging by their latest single, U.K. girl group the Saturdays would certainly be inclined to agree: The track, which was produced by Steve Mac, sees the gorgeous quintet pining after their long-distance loves and ticking off the days on their heart-shaped mini-calendars until their grand reunion. "One month, four weeks, too many hours/ Sunrise, sun fall, I'm growing tired," the girls complain during the soaring chorus, which thumps with a '90's dance-pop energy.

With One Direction and The Wanted making a killing stateside right now, one can only wonder: Are the girls missing their U.K. boy band counterparts? Sure sounds like it.

+ LISTEN TO THE SATURDAYS, "30 DAYS"

5.) Paul Van Dyk featuring Plumb, "I Don't Deserve You"

This wouldn't be a proper round-up without a little EDM to top it all off! German DJ extraordinaire Paul Van Dyk just released his sixth studio effort last week, Evolution. "I Don't Deserve You," one of the best new cuts off of the record, sees the legendary DJ teaming up with dreamy-voiced dance chanteuse Plumb. "I don't deserve you now, but you give it to me anyway," the singer cries out during the 7-minute epic.

After a minute or two pause of tears-on-the-dance floor trance vibrations, the love-struck songstress returns to the speakers: "You're the first thing that I see and the last thing that I think about," she confesses. Um, I think you're being a bit too hard on yourself Ms. Plumb! I think you're good.

+ LISTEN TO PAUL VAN DYK FEATURING PLUMB, "I DON'T DESERVE YOU"

Bradley Stern is a writer from Connecticut. In his spare time, he enjoys organizing his Britney Spears CD collection in reverse chronological order and plotting the various ways in which he will bring down Katy Perry to become Rihanna's best friend. But most of all, he spends his time tweeting musing daily about pop music on his blog, MuuMuse.

Photo credit: Getty Images/Downtown Records