Anonymous 4 are a female a cappella quartet, based in New York City. Their main performance genre is medieval music, although they have also premiered works by recent composers such as John Tavener and Steve Reich.
The name of the group is a pun on the name used to refer to an anonymous English music theorist of the late 13th century, Anonymous IV, who is the principal source on the two famous composers of the Notre Dame school, Léonin and Pérotin.
Anonymous 4 have performed in cities throughout North America, and have been regulars at major international festivals. They decided to make the 2003-2004 season their last as a full-time recording and touring ensemble, although special projects (such as their Gloryland CD and their "Long Time Traveling" Tour) have continued to bring them together on occasion.
The group currently comprises Marsha Genensky, Susan Hellauer, Ruth Cunningham, and Jacqueline Horner (Jacqueline Horner-Kwiatek in more recent listings, following a marriage in 2008). The original lineup included Johanna Maria Rose but not Jacqueline Horner. In 1998, Cunningham left and was replaced by Jacqueline Horner. In 2008, Cunningham returned to the group in place of Johanna Maria Rose. Genensky grew up in California in the foothills of the Santa Monica Mountains; Hellauer was born and raised in the Bronx, New York; Cunningham was brought up in Millbrook, New York; Rose grew up in the village of Grand View-on-Hudson; and Horner is from Monkstown, County Antrim, in Northern Ireland (she won her Green Card in the Diversity Immigrant Visa program, commonly known as the "Green Card Lottery").
- An English Ladymass (1993)
- On Yoolis Night (1993)
- Love's Illusion (1994)
- The Lily and the Lamb (1994)
- Voices of Light (1995)
- Miracles of Sant'Iago (1996)
- A Star in the East (1996)
- A Portrait of Anonymous 4 (1997)
- 11,000 Virgins: Chants for the Feast of St. Ursula (1997)
- A Lammas Ladymass (1998)
- Legends of St. Nicholas (1999)
- 1000: A Mass for the End of Time (1999)
- The Second Circle (2001)
- La bele Marie (2002)
- Darkness into Light (2003)
- Wolcum Yule (2003)
- American Angels (2004)
- The Origin of Fire: Hildegard von Bingen (2005)
- Gloryland (2006)
- Four Centuries of Chant (2009)
- The Cherry Tree (2010)
- Secret Voices: Chant & Polyphony from the Las Huelgas Codex (2011)