1. They're Australian. The four-piece is from Western Sydney, and Calum Hood, Luke Hemmings and Michael Clifford were all school chums before stumbling on a music career in early 2011. Drummer Ashton Irwin, who the rest of the guys knew through mutual friends, joined later in December 2011, when 5 Seconds of Summer played its first show together.
2. They Started With YouTube Covers.
Before they were performing original music, Luke, Calum and Michael posted covers of Blink-182 and Mayday Parade songs -- sometimes using two guitars, other times using bongos, and almost always wearing zip-up hoods or v-neck tees. The video that took off was their acoustic take of Chris Brown and Justin Bieber's "Next 2 You," which has earned 1.1 million YouTube views since being posted in July 2011. On their new "She Looks So Perfect" EP, the guys nod to their past by offering a faithful cover the Romantics' "What I Like About You."
3. They Are, First and Foremost, a Rock Band. Despite opening for One Direction and being composed of four under-21 heartthrobs, 5SOS have carefully underlined the fact that they play instruments, and cite emo-pop groups like All Time Low and Boys Like Girls as influences rather than New Kids on the Block or 98 Degrees. 1D moved away from the bubblegum sound of "What Makes You Beautiful" and towards a more electric guitar-driven sound with last year's "Midnight Memories" album, but 5 Seconds of Summer will not really need to make that transition.
4. Lead Singer Luke Hemmings is the Heartthrob.
He's got the lip ring, the perfectly coiffed blonde hair, the disarming smile, the devastating blue eyes. He's got the most Twitter followers out of all the 5SOS lads (2.17 million) and hundreds of thousands of likes on all of his Instagram photos. At this point, his HSP rating (Harry Styles Potential) is off the charts.
5. Guitarist Michael Clifford Has The Coolest Hair. I mean, when you can describe your 'do as a Reverse Skunk, you know you have the 'Coolest Hair' title on lockdown.
And that's not even counting the blue hair…
6. One Direction's Louis Tomlinson Gave Them A Crucial Co-Sign.
That tweet was sent out three days before One Direction's sophomore album "Take Me Home" was released in November 2012, and right after 5SOS wrapped up a tour supporting Hot Chelle Rae in Australia. Three and a half months later, 5 Seconds of Summer was opening for 1D at the O2 Arena in London, and both acts are currently managed by Modest! Management.
7. First Single "Out Of My Limit" Exploded On YouTube.
Essentially, this was the video -- a straightforward performance clip soundtracked by a light pop-rock track about unrequited love -- that catapulted 5 Seconds of Summer out of the collection of YouTube covers artists, upon its release in late November 2012. Whereas most of their cover clips have earned a few hundred thousand views each on YouTube, the "Out Of My Limit" video has 3.5 million views, and set up their spot on tour with One Direction nicely.
8. They Are Younger Than One Direction and Justin Bieber. The popularity of One Direction and Bieber are not waning, but with all the 1D members and the Biebs now in their 20's, there are empty seats to fill at the male teen pop heartthrob table. Enter 5SOS, who are all still teenagers (Ashton is the oldest at 19 years old, while Luke, Calfum and Michael are all 17). Are 5 Seconds of Summer and 17-year-old Austin Mahone the "new" One Direction and Justin Bieber in the teen space?
9. New Single "She Looks So Perfect" Will Convert Disbelievers.
Like One Direction's "What Makes You Beautiful," which eventually made the haters buckle with its immaculate collection of hooks, "She Looks So Perfect" is a cleanly produced pop-punk confection with a compelling vocal performance from Hemmings and the undeniable line "She looks so perfect standing there/In my American Apparel underwear." Embrace the "The way that you flip your hair gets me overwhelmed" of 2014 while you still have time.
10. They Are Coming To a Stadium Near You. After opening for One Direction on their Take Me Home tour last year and embarking on their first U.S. headlining tour later this month, 5 Seconds of Summer will rejoin the best-selling boy band for their Where We Are stadium tour in North America, performing in 21 cities from August to early October. That means that thousands upon thousands of people who might not be familiar with 5SOS will get a crash course if they arrive on time to the Where We Are show this summer. The 5 Seconds of Summer takeover is underway.