The Whanganui Intermediate pupil cites Bruno Mars and Charlie Puth as his music idols and says his dream is to one day enter the music industry.
"I want to compose some songs ... that would be awesome."
His mother Angela said she was trying to encourage her son to persevere and work hard at his talents. To help him realise how good he was, she uploaded the video to a page called "Aotearoa's most talented" which features many of New Zealand's up-and-coming artists.
"I thought AJ had a pretty good talent and I wanted to share it," she said.
"I certainly wasn't expecting it to take off like it did - that was unexpected."
AJ says he is starting to feel more confident about himself after he won the Whanganui "big busk off" and came second in the Whanganui's Got Talent competition last year.
It capped off what was a big year for him, including being asked to play at the Market Day in Marton and also help support Wanganui Mental Health in Majestic Square.
AJ also plays for the dementia patients at Springvale Manor once a fortnight.
Angela says her son has loved music ever since kindergarten and before he got his own piano would find any chance to play.
"If we were in town he would always run to Paige's bookshop and play the piano and sing."
AJ says going to church when he was little played a big role in his love for music.
"I love singing and when I went to church they had a piano to play, so I just kept nagging my parents until they gave in."
