Now 49, she is still very much on the stage with the group boasting a newly-released album.
Faces to the Sun is coming out “at the right time”, when South Africa needs it.
“It celebrates South Africa,” she said this week ahead of her Mother’s Day performance at Ballito’s Sugar Rush Park next Sunday afternoon.
“There’s some real, serious stuff going on,” said the Wits politics graduate, adding that her music was never overtly political in spite of its effect.
“In my humble opinion, we need to remember that we’re going through another blip. And it’s probably appropriate for a young democracy to have such things.
“However, one must keep the faith and carry on.”
She said music, which could change people’s hearts like politicians could not, gave a sense of what was possible yet again.
“I’m a huge fan of South Africa and I believe we are going to be alright. It’s a wobble and we’ll come out the other side in my humble opinion.”
Johnston, whose favourite dish is curry, lamented that the trip down to KwaZulu-Natal from her home in Johannesburg will be “such an in and out” she won’t be able to explore the culinary delights.
However, a road trip to the province was on the cards with her partner, “a fabulous Canadian man”, when breyani and bunny chows would be on the menu.
Now divorced from Mango Groove founder John Leyden, home for Johnston is Johannesburg’s trendy suburb of Parkhurst, close to where she grew up and attended Greenside High School and performed in the band.
“It’s funky and it’s interesting to see how different it is but it feels like home.”
Back in her youth, 17-year-old Johnston’s being in the band alongside 64-year-old Mickey Vilakazi, who has since died, ended up becoming something of a political statement in itself, she said.
“We weren’t overtly political. The only song that was was Another Country.
“But we changed the hearts and minds of people in a way politicians cannot. We were very lucky to be part of the transition. “Having our first album come out in 1989, the timing couldn’t have been better. South Africa was ready for something like Mango Groove. Being part of that shift is probably what made us.”
Today she feels the power of music when she sees fans who were not even born in Mango Groove’s early days but who know the lyrics.
“The songs have crossed generations,” she said.
She has, however, had to adapt to the younger generation’s attachment to social media.
“I have had to become tech savvy.” She recalled how, back then, a publicist “did it all”.
Now they wanted candid shots of her her doing “bizarre and random things”.
“It’s a different world. People want to be in touch with artists more than before. I need to get used to it and not get embarrassed. I think that surely it’s not interesting but it is.
“I’m getting there.”
Johnston said that as she grew older, the more she saw herself one day living closer to ocean, “somewhere like KwaZulu-Natal or the Cape”.