Mary Halvorson isn’t much one for labels. Jazz, experimental, avant-garde—whatever you want to call her music is fine with her. It’s the sort of categorical freedom that has allowed her to become one of the most innovative guitarists across any genre, leading one recent New York Times reviewer to proclaim her “an unflinching original.” She has performed with musicians such as Taylor Ho Bynum, Jason Moran, Trevor Dunn, Ingrid Laubrock, and her former teachers Joe Morris and NEA Jazz Master Anthony Braxton. As her own band has shifted from three to eight artists through the years, her compositional range has expanded accordingly, gaining new voices to carry out her unconventional ideas. Before she left on a European tour, we caught up with Halvorson to talk about composition, creativity, and Jimi Hendrix.