Common-Tone Diminished Chains
I was sightreading Giulio Regondi's 4th etude recently when this little chromatic passage caught my attention: In the dominant key (B-major), this excerpt showcases a very interesting romantic-style turnaround. In essence, it's just an embellishment of the dominant chord (F#7) as it resolves in the following measure. But Regondi's means of getting there are very hip. Observe how on the third beat, a fully-diminished chord resolves up to an F#7 in 2nd-inversion. That is a prime example of a common-tone diminished chord. This sound is achieved by lowering the 3rd, 5th, and 7th of a dominant chord by one semitone, while maintaining the root (hence the term "common-tone"). Regondi takes it a step further and proceeds to a B-diminished 7th chord before resolving to B-major. Notice how every note of the B-major chord in the 2nd measure is approached from a semitone below? (except for b which is the common tone) After analyzing this fragment of music, I wondere...