Martha Elenor Maguire is an American musician who is a founding member of both the all-female alternative country band The Chicks and country bluegrass duo Court Yard Hounds. She won awards in national fiddle championships while still a teenager. Erwin is accomplished on several other instruments, including the mandolin, viola, double bass and guitar. She has written and co-written a number of the band's songs, some of which have become chart-topping hits. She also contributes her skills in vocal harmony and backing vocals, as well as orchestrating string arrangements for the band.
