Andrew, a former pupil of Glebe Primary School, in Sussex Road, and Vyners School in Warred Road, makes up one quarter of the swing group who will go head to head with other hopeful performers in the ITV show tomorrow night (Saturday May 31).
The 32-year-old is having a second crack at the whip after being given the OK from his wife to leave his job at catering company Tec Line, based in Ashley Road, Uxbridge, and concentrate on his passion.
"I've always sung," said Andrew, who had just performed on ITV's Lorraine show when I spoke to him this morning (Friday, May 30).
"We've got our mortgage and kids now, so she said go for it.
"I wasn't really happy in my job so about this time last year I started testing the water to see if I could make a business out of singing and started performing at weddings and parties.
"I didn't have Britain's Got Talent in my mind but that's just what happened."
Andrew is joined by Sean Ryder Wolf, 33, from Surrey; Adam Chandler, 29, from Kent; and 25-year-old Alfie Palmer from Essex.
"We met through a friend of mine, Anthony Andrews, who's now our manager," explained Andrew.
"We all have a love of the Rat Pack era and wanted to reference that in our name. We also wanted something British too, so that's where 'Jack' came from. Also, we are all very Jack the Lad-type boys.
"Anthony put us all in touch with each other, but the first time we actually performed as a group was in the auditions."
The Jack Pack's first audition was on Valentine's Day (February 14), but BGT's most notorious judge is yet to see them perform.
"Simon Cowell wasn't there because his girlfriend was having a baby," explained Andrew.
"Which is a double edged sword; we were pleased because the pressure was off but now we're anxious we've not seen him yet. He's very influential and you can't read him."
So why Britain's Got Talent, a show where entrants are not only up against other singers, but all sorts of bizarre acts including magicians, impressionists and even a freestyle motor cross display team?
"Britain's Got Talent is an amazing platform. We wouldn't necessarily suit any other show," explained Andrew.
"This is our style of music. We couldn't have gone and done ABBA week on X Factor, for example."
But however they do on Saturday, Andrew says he has had an amazing journey.
"It's so difficult to explain how crazy it's all been," he said.
"There's so many good acts. Who knows what the public want?
"I just want to deliver a good semi-final performance. The thought of winning £250,000 and performing for the Queen hasn't really come in to it.
"It's a massive prize. It's huge, but we're just taking it one step at a time. We don't have any expectations."
Simon Cowell will be joined by judges David Walliams, who was filming in Hillingdon earlier this month, Amanda Holden and Alesha Dixon.
Britain's Got Talent is on ITV 1 tomorrow night at 7pm.