Though these two last described chords of the seventh, which we may call subdominant sevenths, with their deriva tives, are figured in the same way as are the dominant seventh and its derivatives, yet the performer of thorough bass soon learns to distinguish what precise combinations are meant. There are other chords of the 7th, but these of the dominant and subdominant are the most important ; and Are shall now pfoceed to consider the manner in which these and the tonic harmony are interwoven in musical phrases, which indeed constitute, we may say, the substance of all modulations.
In our examples, hitherto, we have confined ourselves to the keys of C major and A minor, leaving it to the industry of the student to write and perform them in different key-s; but as the diligent reader must now be familiar with the tonic and dominant harmonies, and their inversions in dif ferent positions, we think we may, without the risk of con fusing him, write our subsequent examples in different key's. This will both relieve monotony, and assist the student in the exercise of transposition, which, indeed, is a simple business enough, though otherwise accounted of by many. We shall, at least for some time, observe a progressive order both in the major and minor modes.
127. The seventh of the dominant may be struck freely without preparation, or it may be prepared. When me proceed directly from the chord of the key to the dominant, the 7th is of course unprepared. This progression, with the inversions of both chords, is given in the examples following: No. 1. a, both the chords fundamental in the key of C major; at b, the same in the relative minor A, in a different posi tion. No. 2. a, the chord of the key followed by the first de rivative of the dominant in G major ; b, the same in the re lative minor E. No. 3. a, the chord of the key followed by the second inversion of the dominant, in D major; b, the sante in B, the relative minor. No. 4. a, the chord of the key followed by the third inversion of the dominant resolv ing on the chord of 6th, in the key of A major; b, the same in F)'<, the relative minor; here we require E#4 as leading note, which on keyed instruments is struck with the finger key of F1:1.—N. B. This direct progression from the key to 4+ .
the is not so usual as some others which follow, and is considered by some as a license • it has a good affect, how ever, in the course of a strain. 'No. 5. a, the first inversion
of the tonic harmony followed by the dominant 7th, in E major; b, the same in C#4, the relative minor ; here we must have 1M for the sensible note, played on keyed instruments by the finger-key of C No. 6. a, the first inversion of the tonic harmony followed by the first invercion of the domi nant 7th in the. key of B major ; b, the same in that of G*, the relative minor ; here we require F double sharp, signified by the St. Andrew's cross, and played by the finger key of G No. 7. a, the first derivative of the tonic har mony in the key- of F major, followed by- the second deriva tive of the dominant. The reader will observe, that in this example, and in No. 5. a, a perfect fifth between the highest and second parts is followed by an imperfect fifth between the sante parts in similar motion ; but as the imperfect fifth is regularly resolved, this is reckoned quite legitimate by the strictest harmonists. At b, the same progression in the mi nor mode of D. No. 8. a, the first inversion of the chord of the key, followed by the third derivative of the dominant seventh in the major mode of B b. This is a much more usual progression than that in No. 4 ; b, the same in the re lative minor G.
6 The second inversion of the tonic harmony, or 4 on the fifth of the key, is frequently succeeded by the 7 on the same 5 bass, in formal closes on the key ; No. 9. a, b in the major 6 mode of Eb, and minor of C, its relative. The 4 does not easily allow any motion of the bass, except by gradual ascent or descent : therefore this second inversion of the chord of the key cannot well be succeeded by any other derivative of its own dominant except the third, which progression is given in the major of An, and in its relative minor F, No. 10. a, b. This inversion of the chord of the key might proceed to other derivatives of dominant chords effecting a change of 6 key ; or the 4 on the key-note;which is the second inversion of the common chord oldie fourth of the scale, may. be suc ceeded by the first derivative of the dominant, the bass de scending semitone; which is exhibited in the major mode of Db, and the minor of Bb, its relative.., No. 11, a, b. With this example we close this article, and in the next proceed to exhibit examples of the subdominant with the tonic, the dominant, and other harmonies.