All at once she began to sing: “I graze by the Neckar, I graze by the Rhine.” Her voice was warm and pure. At the second verse Knulp joined in and sang the bass part with such sureness and in such a fine deep voice that she listened happily.
– “Early Spring,” Knulp, Hermann Hesse
The song is “Rheinlegendchen,” by Mahler, here performed by Christa Ludwig and the New York Philharmonic, conducted by Leonard Bernstein, in 1967.
[Video source: https://www.youtube.com/watch?v=ZOMu1oKAouE]