Triad Exercise, moving by 5ths
In the previous lesson, we encountered the V-I “authentic” cadence. The ubiquity of V to I in western music cannot be overstated. The bass motion of a 5th, in this case V to I, is, in itself, a common avenue of harmonic expression. Can you hear the bass motion by 5th in these recordings?
In this lesson, we will be exploring bass motion by 5th, restricted to the notes of a major scale, and their corresponding harmonies. We will start by playing all the notes of C major scale, moving down by a 5th
Note that F to B is not a “perfect 5th” (7 semitones), but rather a “diminished 5th” (6 semitones). Again, we are restricting ourselves only to notes within the major scale, thus a motion “down by 5th” is measured in scale steps. In every major scale, there is a diminished 5th when moving from IV down to viiº
Now, we will play all the triads associated to these bass notes, such that the bass note always moves down by 5th.
Like the previous exercise, the large leaps in this passage are both cumbersome to play, and lack a desired smoothness. Instead of moving down by 5th every time, we can alternate steps down a 5th and steps up a 4th. This will contain the exercise within a narrower range of notes, without changing the progression.
This is certainly preferred to the first example, but could be further improved. Interestingly, every chord in this progression shares a note in common with the one before and the one after. By building each chord around each common tone, we can employ the use of triad inversions to play this progression in a manner that is both easier to execute and more beautiful to hear:
If we continue with this pattern, we will succeed in smoothly playing every triad – in all three inversions – belonging to the key of C Major. The example below demonstrates this, with the Roman numerals and inversions labeled.
Here is the same exercise in the key of G major:
And in F major: