During the first strain a melody rises up a fourth several times, slowly from B to E over two bars, then faster from C to F in one bar, and finally even faster up to G in half a bar. The phrase thus gets higher and faster at the same time, before a long sinking phrase brings the melody to rest even lower than where it started. The rhythmic compression and the comparative pitching of these opening phrases is typical of the whole piece, where the whole is considerably more than the sum of the parts. The start of the second strain is built on a duet between soprano and tenor that then turns round letting the tenor lead the soprano for the remainder (with the alto joining in). Byrd here introduces some particularly expressive harmonies. All these elements come together in the third strain; the harmonies are even more pungent, the imitations are at an even closer distance, and the varied harmonic rhythm deliberately slows down.
from notes by Davitt Moroney © 1999