There are two sketches for this piece, and the second sketch dates from Britten's period in the United States. The earlier sketch is on British manuscript paper, and it is possible it was begun at an earlier date.
Work based on text written by W.H. Auden.
2 items
Material has been microfilmed and is available as follows:
Composition sketch: A21, frames 67 - 68
Comp sketch and more: A29, frames 326 - 330
Single page: A57, frames 80 - 81
Archive
https://www.bpacatalogue.org/archive/BBM-o_what_is_the_sound_that_so_thrills
