If you think American alternative-pop band Echosmith's smash hit Cool Kids is about them, you are wrong.

You would be forgiven for thinking so, though. After all, three members of the quartet - all four are siblings - are still teenagers, but unlike their peers, they get to play on stage just about every night and tour the world, too.

But Cool Kids, a catchy anthem that encourages youths to embrace and accept themselves, came from their struggles with their own insecurities about not fitting in, feelings that are commonly experienced by youngsters their age.

Formed in 2009, Echosmith comprises Jamie, 22, Noah, 19, Sydney, 18, and Graham Sierota, 16.

They were in Singapore for the first time last week as part of their first headline tour in Asia, and played a 90-minute show in front of a 1,500-strong crowd at The Coliseum, Hard Rock Hotel last Tuesday.

Speaking at a press conference on the day of the concert, the chatty Sierota clan was missing one member - Jamie, the guitarist. He is back home in California to be with his wife, who is expecting their first child.

Bassist Noah says: "There is new life coming and we're going to be aunts and uncles. We're really excited for Jamie and his wife. It's crazy because there's so much going on amid this."

Indeed, Echosmith have been on a roll since breaking out onto the scene with the chart-topping Cool Kids in 2013, off their debut album Talking Dreams.

The certified platinum track reached the Top 10 of the iTunes singles chart and Top 15 of Billboard's Hot 100 chart. Their latest single Bright has also been heating up the airwaves.

On the inspiration for the song, lead vocalist Sydney says: "We have all felt the desire to fit in, to look like someone else or even be that person. But it's up to you to be okay with who you are because nobody else gets to decide that."

And even with their newfound fame, the Sierota siblings admit they still occasionally feel insecure, especially when mingling with more experienced musicians.

Noah explains: "When you're in the area with other artists and bands, you think they are really cool. Sometimes, we feel left out and awkward not being a part of these other groups."

With their father being producer and songwriter Jeffery David, the Sierota siblings have been making music since childhood, so it was only natural they decided to take their passion one step further and form a band.

To top off the family affair, they are managed by their father and artist mother Linda, both of whom accompany the children on tour. Noah, Sydney and Graham, the drummer, are home-schooled.

Noah says: "Our dad and mum have been pretty supportive of what we do. They've been a part of it since the beginning and we'd definitely be nothing without them; we wouldn't even have had instruments. We're kind of in it all together."

For Sydney, being the only girl among the siblings and having three boisterous brothers means she is often the target of their pranks on the road.

She says with a laugh: "My brothers make fun of me, but I don't really get to control that, unfortunately. I wish I did, but they are uncontrollable."

Like typical siblings, the Sierotas have their fair share of disagreements, though they always try to "talk things out without killing each other".

They also have to put up with one another's bad habits, such as chewing food with their mouths open, something all four apparently have in common.

Sydney says: "It annoys me the most, but all of us do it once in a while. We will be like, 'Close your mouth, Noah, geez.' And then he'll say (the same thing to me) two seconds later."

Still, the tight-knit bunch do not get sick of one another.

Sydney says: "We're always on a big family road trip, it's never ending. We get to really bond and enjoy the time more than we would if we were with just friends.

"There are also fewer people to miss when we're gone from home."