This song by the great English Baroque composer Henry Purcell (1659-1695) sets to music a poem by Colonel Henry Heveningham (1651-1700). Heveningham took the famous opening line of Shakespeare’s Twelfth Night and developed it into an expression of ardour inspired by a (presumably) female singer.
Purcell in fact published three distinct musical settings of the song, all for solo voice with harpsichord accompaniment. The first two, published in 1692 and 1693, are quite similar, and because of this are sometimes both confusingly referred to as the first version. The most widely performed is in fact the second (1693) version, which makes some adjustments to the original melody and sets the key a tone lower. In this form the song was made popular by the mid-twentieth century counter-tenor Alfred Deller. You can watch a good, more contemporary aria performance of this version by the tenor Thomas Cooley, with the accompaniment expanded to a small continuo. This second version of the melody has also been used by The King’s Singers for their own a capella arrangement, which they perform with their usual finesse.
Curiously, the original 1692 version is by far the hardest to find in performance; but it also happens to be the only one which has a freely available (and anonymous) four-part choral arrangement, and so is favoured by choirs – including Gurt Lush. The Auckland Youth Choir have filmed a good performance of this arrangement.