Collegium Vocale Köln is a German vocal ensemble, founded in 1966 as a quintet when its members were still students at the Rheinische Musikschule in Cologne. It is directed by Wolfgang Fromme, who also sings tenor in the ensemble. They are best known as the group for which Karlheinz Stockhausen composed Stimmung in 1968, a work which they had performed more than three hundred of times throughout the world by 1986. The original impetus for the ensemble's founding, however, was an appearance by Alfred Deller at the Cologne Courses for Early Music, and the group has always performed both early and contemporary works. In addition to Stimmung, the Collegium Vocale performed other works by Stockhausen, notably as part of the ensemble of musicians who appeared with him at Expo '70 in Osaka, Japan, between March and September 1970, where individual singers of the group performed Spiral for a soloist with a short-wave radio. From Wikipedia (https://en.wikipedia.org/wiki/Collegi...) under Creative Commons Attribution CC-BY-SA 3.0 (http://creativecommons.org/licenses/b...)