We may apprehend the Difference of perfect and imperfect Instruments, by listening to a Harpsichord, when any Music, where the Key changes often, is played, and to a fine Band, such as the Playhouse or the Opera. We shall find, in the latter, that the Composer has taken Care to make every Transition quite smooth and harmonious; and that tho' the Music be ever so cromatic, yet it never departs from it's melodious Effect. Whereas in an Organ or Harpsichord, even the greatest Performers cannot avoid a disagreeable Roughness in complicated Harmony. Nevertheless, as has been before observed, we must acknowledge the Organ to have Powers which other Instruments have not.
XI.
That a Piece of Music which has Flats set before it, is in a Flat Key on that Account, and vice versa with Sharps.
This is so well known to be an Error, by all those who have arrived at any
Proficiency in Music, that very little need be said about it; however, it is a very common Error.
A Key is not constituted flat or sharp, by having Flats or Sharps at the Beginning of the Piece of Music; but it depends upon the third Note upwards from that Note in which the Music is composed. For Instance, if the Piece is composed in D, and we find that F is natural, or only half a Note from E, then it is in a flat, or flat third, Key; if F is sharp, or a whole Note above E, then the Piece of Music is composed in a sharp third Key. But as there are so many Books extant about Thorough Bass, which give a full Account of this, it will be needless to say any more about it, only to mention it as an Error, among other Errors. The Reader shall not be tired any more with Music at present, but for Variety we will shift the Scene a little while.