Hall, 24, said: "If you played in that session you were guaranteed a spot, if you could play the music."
Hall has the talent of being able to play pretty much any instrument he picks up.
He says he can play "piano, alto saxophone, clarinet, all brass instruments, except trombone.
"I'm a massive band geek. I listen to so much concert band music it's not funny."
He started playing French horn out of a shortage of players of the instrument.
"Someone was like, 'Hey, here's a horn', and I was like, 'OK'," he said.
It was much the same for Ben Andrews, 16. He started playing the tuba while on a trip to Rarotonga three years ago when another tuba player was needed.
Before the tuba, Ben played clarinet but finds it "too common". His mum, Lucy Andrews, said he loved having his own niche.
Scott first got into music as a part of the Year 7 programme at Pompallier Catholic College.
He finds he gets most of his musical influence from watching YouTube videos.
The four boys belong to Whangarei Youth Music in Lower Dent St in Whangarei, which Ms Andrews said was like a tight family with a lovely atmosphere, with everyone, including the parents, encouraged to have a go.