With the Chicago-based ensemble His Majestie's Clerkes Hillier recorded early American repertoire such as the works of William Billings on the 1992 album A Land of Pure Delight.
Theatre of Voices’ repertoire covers a wide range of genres and stretches from the earliest notated music to modern sound art installations and contemporary opera.
This inspired commissioning of even more Nordic repertoire and resulted in a North Atlantic Tour in 2019 that included works from Greenland, Iceland, Faroe Islands, Denmark and Estonia featured on both concerts and local workshops.
Hillier has recorded a number of solo albums, some with harpist Andrew Lawrence-King on the Harmonia Mundi, ECM, EMI, Finlandia and Hyperion labels.
From 1980, Hillier has held a variety of academic appointments over the years, most recently as Director of the Early Music Institute at Indiana University Bloomington.