Grantis hails from Mississauga, Ontario, just outside Toronto. She fell in love with classic rock as a child learned to play guitar before she was ten after becoming enamored of guitar players from Jeff Beck and B.B. King to Angus Young and Jimi Hendrix. She was given her first electric guitar at age 14 and was later awarded a jazz studies scholarship to McGill University in Montreal. After graduation, she relocated to Toronto and began working as a session and live player with local artists until 2010, when she joined Shakura S'Aida as a guitarist, co-writer, and musical director of the artist's backing band the Solrawkestra. They toured together as part of the Ruf Records' Blues Caravan Tour in 2010 with Coco Montoya. In addition to her session and live work, she became the music director for the CBC. Grantis also founded the Donna Grantis Electric Band, a fusion rock trio with drummer Roger Travassos and bassist Steve Zsirai. The group issued its debut album Suites on Diamond Gem Records in 2012.
Prince discovered Grantis' work online and, in November 2012, invited her to Paisley Park to audition for the 3rdEyeGirl band. Grantis moved to Minneapolis from Toronto and spent four years playing in both 3rdEyeGirl and New Power Generation; her tenure ended with Prince's death. In addition to playing guitar, Grantis penned the title track to Plectrumelectrum. After Prince's passing, Grantis and her husband lived in Los Angeles and New York briefly before resettling in Minneapolis. There she formed her jazz-fusion quintet with bassist Cody McKinney, drummer J.T. Bates, keyboardist Bryan Nichols, and percussionist Suphala. They made their live debut in August 2017 at The Dakota, the same venue where 3rdEyeGirl played its first gig. Four years earlier, Grantis had met Pearl Jam's Mike McCready after a 3rdEyeGirl show. The pair hit it off, and Grantis joined his band on-stage on two successive evenings for encores. She recruited McCready to play on her newly formed quintet's debut single, "Thrashformer" b/w "Violetta," issued by Diamond Gem/eOne in 2018. Grantis and her band released the full-length Diamonds Dynamite (it included the two tracks with McCready) in March of 2019, followed by a North American tour. ~ Thom Jurek, Rovi