Michael Rhodes, an American opera singer and highly sought-after vocal coach who trained stars including German tenor Jonas Kaufmann, has died at the age of 89.

Anne Foegen-Rhodes said her husband died Sunday in the west German city of Trier where he had lived for many decades.

Rhodes, a baritone, began his professional singing career in 1947 at New York City Opera playing Jochanaan in Salome.

He moved to Europe in 1951 and took guest roles at the Opera National in Paris and Milan's La Scala.

In the same year he became the first American after World War II to sing at Berlin's Deutsche Oper.

From Trier, Rhodes conducted numerous choirs and musicals for American service families at the nearby airbases of Spangdahlem and Bitburg.