With millions of views online via her YouTube channel and fans all around the world, her current status as the next big thing is a long way from her troubled teenage years.
"I was a complete drug addict," Tash recalls. "I really was a complete drug addict.
"Doing every drug apart from heroine."
When she was 17 she developed drug-induced psychosis and it took months of therapy and supervision before she says she was able to get back to a good place.
"It's like I opened a can of worms and I couldn't put them back away. It took ages to put it back together.
"You wouldn't have even understood the kind of person I was if you saw me in that state.
"It was hell and I put myself in that position.
"That's the worst because you can't blame anyone for it because you did it."
Getting her first guitar at the age of three as a gift from her grandfather, Tash has now mastered over 10 instruments including guitar, bass, trumpet, flute, percussion and saxophone.
"My goal is to just be able to play as many instruments as I possibly can," she says.
"I learnt everything to do with music in my own time."
After failing to get a regular job, Tash turned to busking on the streets of Melbourne to get by and she says it taught her a lot about having a strong work ethic.
Yet her big break came thanks to the internet and her recordings going viral on YouTube.
"I just started filming my jams," she says.
"My mum got me a GoPro for Christmas and I was like well, I'm going to put it to use.
"It just got shared and shared and shared and I was like whoa, it was like 10,000 extra followers over night and then it just kept happening and happening and happening.
"I love the fact that there are so many people who have come to appreciate what I'm doing, that is just the best feeling in the world."
Thanks to Busker Stories for additional footage.