Composer, vocalist, director/choreographer, and auteur Meredith Monk has always been interested in the voice as an instrument, rather than as a delivery system for words. Over more than four decades of work, she’s developed ways of working with the voice that make it sound not like one instrument, but many. In her music, you usually don’t need words to tell a story or evoke an emotion; her works, which often include film, dance, or other media, can have a strong narrative to them. Take for example her newest album, On Behalf of Nature. You can probably guess what that’s about, but we asked anyway as Meredith Monk and Vocal Ensemble performed live in the Soundcheck studio.