Simplify the following text for a Grade 6 native English-speaking person.
Original: In 1953 , he founded the period-instrument ensemble Concentus Musicus Wien with his wife , Alice Hoffelner . The Concentus Musicus Wien is dedicated to performances on period instruments , and by the 1970s his work with it had made him quite well-known .
Simplified: He started a group called Concentus Musicus Wien .