A £1.5m album deal with Sony, a number one debut album that sold more 245,000 copies and a top ten single, not bad for a vocal group singing opera.
But in 2007, G4 called time on what had been a meteoric three years since they came second in the inaugural XFactor to Steve Brookstein and went their separate ways.
For one of those, Ben Thapa, it gave him time to go back to college and work on his debut solo record that came out three months ago.
But why take that risk when you are in what looks a very successful group like G4?
"It was a hard decision," says Thapa.
"It lasted three years and that's a big difference between me being 22 and me being 25.
"Most people when they leave college the first thing they do is sign on.
"I was lucky to go straight into this great job for three years.
"But there is a difference between that and what you want to do with your life.
"We just got to the agreement that we all had different dreams and ambitions."
This Sunday, Thapa will be performing songs from his album, Songs From My Childhood, as well as duets with soprano Philippa Lusty at Southfields Baptist Church in Wimbledon Park Road.
It is far cry from performing in front of millions every week on the XFactor, an experience Thapa still looks back on with a smile.
"It was the first series that had done and we had seen the DVDS they made of the failed auditions and, to be honest, we thought we would end up on one of them," he said.
"It was a bit of a laugh and a joke and we never thought anything would come of it.
"Then it got to the third week and Louis Walsh said there was record label interest and we were completely blown away.
"It was an amazing rollercoaster of a time and there are things I know that happened that must have just passed me by.
"It was an excellent experience and we went to all these amazing parties and met all these incredible people, I remember buying Ozzie Osbourne a drink when not long before I had been watching him on television."
Ben Thapa with Philippa Lusty, Southfields Baptist Church, Wimbledon Park Road, February 27, 7.30pm, £7. Call 07947 220028 or visit benthapa.com.
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