Theatre of Voices gave its first official concert in June 1992 at the Berkeley Early Music Festival. Hillier had actually presented concerts of modern music in 1989 in which his early music vocal group the Hilliard Ensemble used the name Theatre of Voices. The development of the group that would become Theatre of Voices began in 1990 when Hillier took a teaching position at the University of California. The formation was not finalized until that 1992 debut concert. The group later moved its base of operations to Bloomington, IN, where Hillier relocated to serve on the faculty of Indiana University School of Music (Early Music Institute). When Hillier moved to Copenhagen in 2003, the ensemble also expanded it's geographical horizons.
The ensemble's first recording was issued in 1994, William Byrd: Motets & Mass for Four Voices, on the Harmonia Mundi label. By then the group was carrying a busy schedule and over the next decade would appear at major concert venues throughout the Americas and Europe, including New York, Paris, Berlin, and Utrecht. It appeared on a six-part nationwide syndicated radio broadcast for the series Millennium of Music and also on the radio program St. Paul Sunday Morning.
In 1997 Oxford University Press published Hillier's book, Arvo Pärt. That same year, Hillier led the ensemble in a recording of Pärt's sacred works on Harmonia Mundi, entitled De Profundis, which made Billboard's Top Ten. A second popular recording of the composer's works by Theatre of Voices, entitled I Am the True Vine, was issued on the same label in 2000. The ensemble has remained active both in the concert hall and on recordings in the new century. The 2006 schedule included a tour of the United Kingdom in January and an appearance at the ILIOS Festival in Norway, the ensemble presenting, among other works, Stockhausen's Stimmung. In 2006, the group released Cantigas on Harmonia Mundi. The group's world premiere recording of David Lang's Pulitzer Prize-winning Little Match Girl Passion won a Grammy Award in 2010 for Best Small Ensemble Performance.