Among the prestigious ranks of English vocal ensembles specializing in early music, longevity and musical versatility placed the Hilliard Ensemble in a class almost of their own. Founded in 1974, the ensemble grew from the vision of baritone Paul Hillier and three other singers, who set out to explore the then-less-heard musical riches of the Middle Ages and Renaissance, though they soon expanded upon that vision. In the 1990s, the Hilliard Ensemble were featured on numerous recordings of the works of Arvo Pärt, and a collaboration with Norwegian jazz saxophonist Jan Garbarek yielded the crossover hit Officium in 1994. They appeared with Arditti Quartet performing the music of Wolfgang Rihm in 2009, and with Fretwork in 2011 performing compositions by Nico Muhly. 2014's Transeamus was the last album the group recorded before retiring at the end of that year; it marked a return to the music of the 15th century.