The Soweto-born performer, whose second album A Glimmer of Hope was released in June, prides herself on being able to do all forms of music.
"People label me an opera singer because they feel comfortable with that," she told me. "But I've always done everything, from opera to gospel."
But it will be jazz, and her unique interpretations of the music, that will be under the spotlight when she performs with her band at the Standard Bank Joy of Jazz at the Bassline in Newtown on August 23.
She will join an illustrious line-up that also includes South African jazz giant Abdullah Ibrahim, Grammy Award winning trumpeter Terence Blanchard, Grammy Award winning tenor saxophonist Eddie Daniels and celebrated pianist Ahmad Jamal (see above).
"I paid for my opera studies by singing jazz in the clubs," she revealed and she is looking forward to seeing how people respond to her jazz interpretations.
"It will always have that crossover sound to it. My own history is not in classical music. It's very much jazz and I have been doing these arrangements for the past seven years."
Sibongile, who is a former Standard Bank Young Artist recipient, is delighted to be performing at Joy of Jazz for the first time. She will unveil a repertoire that contains material from her new album, as well as some earlier compositions.
One of her favourite interpretations which will be showcased, she told me, will be Bach's Air on a G String and she admitted she cannot wait to see the reaction of fans to her version.
Earlier this year Mngoma was busy recording her album: "It was crazy because I was also producing it, something I haven't done before," she said.
She described it as a mixed album as her music has always been eclectic. "It has classical music, opera, jazz, gospel – everything that I have sung over the years is on the album.
"Basically I used a lot of existing material but I put my own spin on it. I arranged it my way and did my own interpretations. On the album, I have embraced what I enjoy doing and I find when I'm honest about where I come from, people enjoy it more. If I try to please the opera crowd or the jazz crowd it doesn't work. They are never ever pleased. When you come from an honest place and you, basically, say 'this is me and this is what I enjoy' then it usually makes them happy."
She is a spiritual entity who has a strong faith and a belief in herself. Her record is on her own label and she shouldered the cost of the production. "I decided I was going to record the album, I didn't know where the money was going to come from and I didn't know what would happen. But I went ahead."
She believes she heals people through her music: "Sometimes people don't understand the words but when they hear the music it has an impact."
- Sibongile Mngoma performs at The Bassline on Friday August 23.