For instance, Gam-ut the lowest note then recognised in the scale, is called 'the ground of all accord.' A-re, I suppose, represents the lover's sigh 'to plead his passion.' B-mi, may be twisted into 'Be mine,' by the light of the remaining words in the line; while 'D sol re, one cliff, two notes have I' obviously refers to Hortensio's disguise. The 'cliff' is what is now called a 'clef,' or 'key,' because its position on the staff gave the 'key' to the position of the semitones and tones on the various lines and spaces. The six notes here mentioned are the G, A, B, C, D, E, in the bass staff. They could only be written (as they are yet) in one clef—namely, the F clef. The expression 'two notes have I,' as applied to the D, means that, in the key of G, D is called Sol; while in the key of C it would have the name Re; just as Hortensio is Hortensio, and at the same time masquerades as a singing-master.
It has been mentioned that the art of adding an extempore counterpoint to a written melody was called 'descant.' The written melody itself was called the 'Plain-song,' and hence the whole performance, plainsong and descant together, came to be known by the term 'Plain-song,' as opposed to the performance of plainsong with a written descant; which was known as 'Prick-song.'
Morley gives us a clear idea that the extempore descant was often a very unsatisfactory performance, at any rate when it was attempted to add more than one extempore part at a time to the plainsong. As he says—'For though they should all be moste excellent men ... it is unpossible for them to be true one to another.' The following passage will be more clear on this light.
H. 5. III, ii, 3. Fight at Harfleur.
Nym. Pray thee, corporal, stay: ... the humour of it is too hot, that is the very plain-song of it.
Pistol. The plain-song is most just, for humours do abound.
* * * * *
L. 41.
Boy (speaks of the 3 rogues).... They will steal anything, and call it purchase. Bardolph stole a lute-case, bore it twelve leagues, and sold it for three half-pence.