��By the stave for the naturals we may restore the tuning of the Guido scale of the earliest organs and clavichords which had only the Bb AS an upper key in two octaves. These would be provided for either by tuning up from the G <a minor third) or down from the F (a fifth), all the intervals employed being approximately just. We may also suppose that from the introduction of the full chromatic scale in organs before 1426, to the date of Schlick's publication 1511, and indeed afterwards, such a groundwork as Am merbach's may have sufficed. There was a difference in clavichords arising from the fretting, to which we will refer later. Now, in 1511, Arnolt Schlick, a blind organist alluded to by Virdung.inhis ' Spiegel derOrgelmacher' (Mirror of Organbuilders) a work which the present writer, aided by its republication in Berlin in 1869, has brought under the notice of writers on music came out as a reformer of tuning. He had combatted the utter subordination of the sharps or upper keys to the natural notes, and by the invention of a system of tuning of fifths and octaves had introduced a groundwork which afforded a kind of rough-and-ready un- equal temperament and gave the sharps a quasi independence. This is his scale which he gives out for organs, clavicymbals, clavichords, lutes, harps, intending it for wherever it could be applied.
���He gives directions that ascending fifths should be made flat to accommodate the major thirds, particularly F A, G BJJ, and C E, excepting Gg, which should be so tuned to Eb, as to get a tolerable cadence or dominant chord, the common chord of E, to A. The Gg to the Eb, he calls the ' wolf,' and says it is not used as a dominant chord to cadence Cj. Indeed, from the dissonance attending the use of Cg and Ab, they being also out of tune with each other, he recommends the player to avoid using them as keynotes, by the artifice of transposition.
The fact of Ammerbach's publication of the older groundwork 60 years later proves that Schlick's was slow to commend itself to practice. However, we find Schlick's principle adopted and published by Mersenne (Hannonie Universelle, Paris, 1636) and it was doubtless by that time established to the exclusion of the earlier sys- tem. With this groundwork Mersenne adopted, at least in theory, Equal Temperament [see TEMPERAMENT], of which in Liv. 2, Prop. xi. p. 132, of the before-named work, he gives the correct figures, and in the next volume, Prop, xii, goes on to say that equal temperament is the most used and the most convenient, and that all practical musicians allow that the di- vision of the octave into twelve half-tones is the
easiest for performance. Mr. Ellis, in his ex- haustive Lecture on the History of Musical Pitch (Journal of the Society of Arts, Appendix of April 2, 1880), considers corroboration of this statement necessary. We certainly do not find it in Mersenne's notation of the tuning scale which we here transpose from the bari- tone clef.
��Let Feintet. The Sharps and Flats.
���For the tuner's guidance the ascending fifths are marked as flat, the descending as sharp, but the last fifth, Gj Eb, is excepted as being the ' defect of the accord. ' With this recognition of the 'wolf it is clear that Mersenne was not thinking of equal temperament. But Schlick's principle of fifths and octaves had become para- mount.
We will now go back to the interesting 'gebunden'orfretted clavichord. [See CLAVICHORD and TANGENT.] The octave open scale of this instrument is F G A Bb C D Eb F, or C D Eb FGABbC, according to the note which may be accepted as the starting-point. Both of these are analogous to church modes, but may be taken as favourite popular scales, before harmony had fixed the present major and minor, and the feeling had arisen for the leading note. We derive the fretted clavichord tuning from Ammerbach thus:
��Later on, no doubt, four fifths up, F C G D A and two fifths down F Bb Eb, would be used with octaves inserted to keep the tuning for the groundwork, in the best part of the keyboard for hearing. We have found the fretted or stopped semitones which included the natural B and E, adjusted by a kind of rough temperament, in- tended to give equal semi mean-tones and re- sembling the lute and guitar semitones.
When J. Sebastian Bach had under his hands the ' bundfrei ' or fret-free clavichord, each key having its own strings, he could adopt the tuning by which he might compose in all the twenty-four keys, from which we have the 48 Preludes and Fugues. 1
Emanuel Bach ('Versuch/ etc., Berlin 1753) gives, p. 10, very clear testimony as to his own preference for equal temperament tuning. He says we can go farther with this new kind of tuning
He did not get this tuning on the organ, It would appear, although his preference for it is shown in Mr. Ellis's 'History of Musical Pitch ' already referred to. (See the ' Journal ol the Society of Arts,' March 5, 1800).