Hi Benjamin,
On the matter of harmony changing once or twice a measure, I don’t intend any prohibitions on switching between five and one chords. Harmonic rhythm, or harmonic tempo, is the rate at which chords change in a musical composition. Harmonic rhythm can be slow or fast. For example, “Eternal Father, When to Thee” has a fast harmonic rhythm; the chord changes every quarter note. “Holy God, We Praise Thy Name” has a slower harmonic rhythm; for the most part, the chord changes every measure. It’s not that one song is slower than the other; but they have a different rate of change.
In the “The Way of Peace,” does the harmony change every quarter note? every half note? If I were you, I’d consider reworking this piece just to establish some large-scale patterns in the piece. Your first two-measure phrase has a fine progression of 1 (with a fluctuation to 5) to 4, then a cadential 6/4 to 5 in the second measure. In the third measure, I am surprised by a sudden 6-4-1-4-1 progression. I would consider making the second phrase a little more like the first phrase. In the first two measures, the felt harmony changes once per measure; in the second two measures, it changes almost every quarter note. In measures 9-11, the song changes back to a very slow harmonic rhythm, which is sure to discombobulate a lot of singers. There are ways to set patterns of fast and slow, so I would suggest reworking the harmonies until it feels exceedingly natural to sing.
