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

Three years ago, life got cold when Girls Aloud announced they were going on hiatus. Now -- as confirmed by a countdown that just popped up on their website this morning -- the almighty troupe (and the closest girl group torchbearers for the Spice Girls legacy) are officially coming back. While I slowly rock back and forth in my room with a Girls Aloud singles collection box set clutched tightly in my arms awaiting their imminent return, I thought I'd highlight just some of the Aloud's brightest moments (don't make me pick a favorite -- talk about Sophie's Choice.) Soon, we'll have even more to celebrate in 10 days. Aloud Forever!

1.) "Sound of The Underground"
The song that started it all: Filled with twangy '60s surf guitar, skittering drums, and sultry come-ons that just won't quit ("Disco dancing with the lights down low..."), "Sound of the Underground" sounded less like an early '00s radio hit and more like Nancy Sinatra being thrust into the U.K. drum 'n' bass scene. And yet, it worked: The song shot to No. 1 on the charts -- their first of 20 consecutive Top 10 hits over the next seven years -- removing the title of "Reality TV Competition Winners" from their name and formally positioning the Aloud as THE girl group to beat for the next decade.

+ LISTEN TO "SOUND OF THE UNDERGROUND"

Listen to more Must-Hear Girls Aloud songs after the jump.

2.) "Graffiti My Soul"
From the very first gritty guitar strum in the song's opening seconds, "Graffiti My Soul" is an instant Aloud classic. Included on their 2004 sophomore record What Will The Neighbours Say? (and originally offered to Britney Spears for In The Zone back in 2003, which sadly never came to be!), the track is a nonstop explosion of ferocious declarations ("Spike heels and skintight jeans/ I got a fist full of love that's coming your way, baby!") and genius kiss-offs ("Your kisses taste of cyanide/ and that's no good for me!") on top of an adrenaline-inducing strut. "Graffiti My Soul" saw the girls coming into their own, wielding sharp stilettos -- and even sharper tongues.

+ LISTEN TO "GRAFFITI MY SOUL"

3.) "Biology"
"Biology" may not be the single greatest song of Girls Aloud's discography, but it could possibly be their most defining: Packed full of nonsense lyrics ("I got one Alabama return that'll take me far away from you"...WHAT?!), propulsive drums, and enough Xenomania-produced hooks to craft about 10 brilliant pop songs, the track completely embodies their signature style. It's fiercely catchy, and like so many of their classics, the song's structure is (brilliantly) erratic. By 2006, the Girls Aloud brand was firmly established. You can't mistake their biology.

+ LISTEN TO "BIOLOGY"

4.) "Call The Shots"
By the time the Almighty Aloud released "Call The Shots" in 2007, the girls were already on their 17th single of their career. And then, they raised the bar yet again -- or rather, the bet: "Just 'cause you're raising the bet and call the shots now/ It really doesn't phase me how you spend your time," the girls croon atop the song's hypnotizing electronic pulse. Every millisecond of this song is an exercise in pop perfection, from the heaven-sent coos in the distance, to the endlessly catchy chorus, to Nicola's heartbreaking bridge. "Call The Shots" isn't just one of the (many) highlights of Girls Aloud's stellar career -- it's one of the best pop songs of the past decade.

+ LISTEN TO "CALL THE SHOTS"

5.) "Untouchable"
And finally, the song that deserved so, so much more: Released back in 2009, "Untouchable" was the Almighty Aloud's first time ever charting outside the Top 10, and cruelly, with one of their most stunning songs to date. The 6-minute opus is nothing short of a masterpiece, gliding across wintry electronica and surging synthesizers. "Through wind and rain we got here..." Nicola tenderly begins. From there, it's nothing but endless chills and sob-inducing lyricism ("Without any meaning, we're just skin and bone/Like beautiful robots dancing alone" -- TEARS!) This song alone is the reason why the Aloud are simply unmatched.

+ LISTEN TO "UNTOUCHABLE"

Bradley Stern is a writer from Connecticut. 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 musing daily about pop music on his blog, MuuMuse.

Photo credit: Getty Images