He said the school had a huge influence on where he was now. The singer ran a workshop with students at the school to help them learn the music to audition for the school production of Westside Story.
"Auditions can be such a nervous time they don't get their abilities across, this may help them be a bit more confident."
Among the students was Year 12 Neeve Coumbe, 16, who had been in previous productions at the school.
"I love performing ... I've been taking singing lessons my whole time here and speech and drama," she said.
Neeve said the workshop with Thurston gave her hope to reach her own aspirations of working overseas.
"I love performing on stage. I'm a pretty shy person I guess but I tend to hide that on stage."
John Paul College drama teacher Candice Stevenson said learning from a former student was inspiring for the current students.
"They can connect and see, especially with him being a boy, it's nice for them to see singing can be a cool and you can make a career out of it," she said.
"It helps they are not going into auditions blind. Musicals can be a scary thing if you're not a singer. It opens it up to the rugby players and the scientists and anyone who wants to participate."
The workshop was the second Thurston had run at the school.
The school was also going to run a stage combat workshop before auditions.