A big yes to Sequentia here, although I think I lost touch with the Visions from the Book album way back when. Top ones include their innumerable albums of Hildegard (soon to be saint???) - chief of which is the vinyl boxset of their first recording of the Ordo Virtutum from 1982. My favourite of theirs, however, is their debut album Spielmann und Kleriker (um 1200 (Minstrel & Cleric) from 1980 which features near definitive takes on Olim Suder Herculis and Samson dux Fortissime by a basic quartet of Barbara Thornton, Benjamin Bagby (voice & harp), Margriet Tindemans (fiddle) and Crawford Young (lute & gittern). A truly remarkable album in every sense - never seen it on CD though...