The vocal group Anonymous 4 formed in 1986, originally comprising Johanna Maria Rose, Susan Hellauer, Ruth Cunningham and Marsha Genensky. So named in honor of the designation given by musicologists to the unknown 13th-century Parisian student whose writings detailed the vocal polyphony he heard at the Cathedral of Notre Dame, the ensemble's performances also explored medieval chanting and polyphony, combined with elements of poetry and narrative; debuting in 1992 with An English Ladymass, the Anonymous 4 immediately topped Billboard's classical music charts, a feat repeated by their 1993 follow-up On Yoolis Night. Subsequent efforts include 1995's The Lily and the Lamb and Miracles of Sant'iago, 1996's A Star in the East and 1997's 11,000 Virgins. After completing A Lammas Ladymass, Cunningham left the group in 1998 and was replaced by Jaqueline Horner. Legends of St Nicholas followed a year later. ~ Jason Ankeny, All Music Guide