In music theory, a cadence is a “melodic or harmonic configuration that creates a sense of repose or resolution” (thanks, Wikipedia; thanks, Harvard Dictionary of Music). The most basic cadence, also called authentic or standard cadence, ends in the chords V-I. (If you don’t know what that means, here’s some basic music theory: V refers to a triad built on the fifth degree of the scale, I to a a triad built on the first degree of the scale. You use Roman numerals to indicate a triad.) Wikipedia says that it is “virtually obligatory” to use V-I as the final cadence in a tonal work.
But there is another, specialized cadence called the plagal cadence. The plagal cadence is IV-I, also called the “Amen” cadence, because it is used for the “Amen” at the end of most hymns, and probably in some other works. To me, the plagal cadence has always felt even more final than the standard cadence, thanks to many, many years of going to church, begun early in childhood.
A few months ago, I watched “Phantom of the Opera” for the first time. I remember at some point hearing a sequence of chords that inspired in me a really profound sense of peace and resolution. I can’t remember when it was: at the end? Or during one of the songs, right before a singer began to sing? At any rate, I began thinking of it as a “super-plagal cadence.”
Thinking about it a few days later, I remembered one other place where I had heard a cadence like that: in Dvorak’s Symphony No. 9, “From the New World.” It is the beginning of Mvt. 2, Largo, and takes 7 chords, before the appearance of the folk-song-like theme. I meant to look at Dvorak’s score sometime and figure out what the chords were. I’m going to do that soon, but wanted to make a note of the connection, as I saw it, first.
I’m not really sure there is anything “plagal” about these cadences. It’s just the way I thought of it, based on my emotional reaction to them. Does anyone know where I’ll find the passage I’m referring to in “Phantom”? I’m pretty sure I still have that recording on my DVR; I can find it in time, but I thought I’d “ask Dr. Internet” first.