The teenager from London performed Love Yourself by Justin Bieber in his bid to get the coaches turning at the weekend.
Coming from a big, super-close family, Septimus has the support of his brood of younger siblings, who are all very proud.
While they were watching on back stage, the coaches were listening in front and centre with Sir Tom Jones turning to select Septimus for his team.
It turns out that The Voice UK wasn't Septimus' first choice in talent shows, originally auditioning for The X Factor where he didn't make it past the first round.
He told the Radio Times: “I did audition for X Factor, but I only did the producers auditions and I didn’t get to audition for Simon [Cowell].
“I feel like I like the way The Voice format is, you have to be really, really good because there are no bad singers and that’s what I think makes it a really good competition for viewers at home and of course us singers as well."
Septimus - real name Septimus Kamara - went on to say he wasn't concerned that The Voice UK has so far failed to produce a star like The X Factor.
He said of the show's move to ITV: "They’ve got new coaches, it’s a whole new format that’s different. Because for this one, the record label is fully involved from the start. For the first time ever the prize is a record contract so that gives a bit more of determination from the artists’ viewpoint to say ‘OK, if I win I know straight away I’m in the industry’.
“It gives that extra edge to see that the record label are saying ‘This year, we want to turn the winner into a huge artist’. I think this year the winner will be the first breakout star from The Voice UK.”
The Voice UK 2017 will return next Saturday night on ITV.