Originally from Winchester, Kentucky, Brenna MacMillan began playing banjo at the age of nine. Brenna performed frequently in the Lexington area which led to opening for J.D. Crowe and Bobby Osborne. Attending Berea College, Brenna played with the Bluegrass Ensemble under Al White and was awarded the Red Foley Memorial Music Award in 2018. After graduating, Brenna moved to Nashville and started Theo & Brenna Band with her brother Theo. Their full bluegrass band toured for several years, releasing two albums. Brenna plays with a variety of Nashville artists, tours with country act Kimberly Perry, and can be seen making guest appearances around town and collaborating with musicians on social media, where she has a substantial following.