In Shakespeare’s Henry V
(Act IV, sc 4), a French soldier greets Pistol, calling him a man of quality. ‘Quality? Calen O Casture me’ he replies, rather mysteriously, a probable reference to the song whose melody is used in this set of variations. Following a simple statement of the tune in C major (Ionian mode), there are five other variations. The first three gradually allow the left hand to take a predominant role, until the quavers at last break out in the right hand and lead to a final variation of greater exuberance. This is one of the most charming and tuneful of all Byrd’s sets of variations on popular Elizabethan tunes and may date from the 1590s. The lute stop, heard here in the left hand in the first part, was common on Flemish harpsichords of the period.
from notes by Davitt Moroney © 1999