Put together by former American Idol judge Simon Cowell, pop classical vocal quartet Il Divo were immediately dismissed by critics when they made their debut in 2004.

Naysayers also insisted that the success of their No.1 debut that year was a fluke.

After a dozen years, they have sold more than 30 million albums and performed countless shows worldwide. The group have proven that they are no lightweight, says Swiss member Urs Buhler.

"Il Divo are now at a comfortable place where we don't have to prove anything anymore, it's really nice," he says in a recent telephone interview ahead of their show at The Star Theatre on Monday.

"We were newcomers 12, 13 years ago. You have the first album, which was very successful and then everybody thinks 'Ah, that's probably gonna be it.' You got the second album which is again very successful.

"Then people kind of wait for you to fail and just for you to be over, because most pop acts are not around for that amount of time."

The group, which also comprise Spaniard Carlos Marin, American David Miller and Frenchman Sebastien Izambard, have released seven studio albums and two live albums.

They have also garnered accolades such as the Artist of the Decade award at the Classic Brits awards at the Royal Albert Hall in 2011.

"We are very lucky, I think," Buhler says during the call from South America, where they were on tour.

"The kind of music we do and the kind of audience we play to, it's a more mature audience and they like what they like and they don't change with the fashion stream.

"So far we are somewhere where we can really concentrate on making the greatest music we can and bring that to our audience every time when we release a new album or new tour."

The current global tour is in support of their latest album, Amor & Pasion, released in November last year.

It is their first to be sung in just one language, Spanish, and includes songs such as A Las Mujeres Que Ame (To All the Girls I've Loved Before) and Besame Mucho.

Fans who are going to the show are in for a treat as all four members will be showing off some nifty moves together with their back-up dancers.

He says: "We dance with them, tango, salsa and cha cha, classical Latin dances. It fits with the music, a lot of these songs from the new album are dances, tangos, boleros, mambo so we can finally bring that element of dance into Il Divo."

Despite still being signed to Cowell's music label, Syco Music, Buhler says that the British music mogul's involvement with the group these days is "next to none".

"He's still our boss, but we're not working with him anymore. He's more a great old friend, he's not really involved, not even in the executive production of the album. I love him, I think he's a great guy."