The type of cadence that we’re going to talk about here is a harmonic cadence. Simply put, a cadence formula of chords that signal the end of a phrase (musical sentence) or musical idea. We talked a bit last time about the big cadences in Sor’s B minor etude, and we’ll get into a some more detail and examine all the cadences in the piece.
Cadences can be put into four big categories: Authentic, half, deceptive and plagal. We’ll take a look at each category individually.
An authentic cadence is a cadence that moves from V or V7 to I or i. In the post on tonic and dominant I mentioned that the dominant (V7) chord has two “tendency tones” that beg for resolution to a tonic chord. The 7th of the dominant chord must resolve down two the third of the tonic chord and the third of the dominant chord (the leading tone) must resolve upwards to the root of the tonic chord.
In a Perfect Authentic Cadence (PAC) the harmonic progression is V or V7 to I with both chords in root position, and the tonic chord has the root or first scale degree as the melody (highest) note on the chord. Here’s an example, notice that the tonic note (C) is in the highest voice of the C major (tonic) chord.
An imperfect authentic cadence (IAC), like the PAC, utilizes the progression V or V7 to I with both chords in root position. The difference is that now the highest voice of the chord doesn’t have to be tonic. In this example the top voice is an E, the third scale degree.
Half cadences are cadences which end open. That is, they want more! These types of cadences are genearally the weakest and demand that another musical idea be started that closes the thought in the next phrase or section. A half cadence is when a phrase or section ends on V or V7.
Sounds tricky doesn’t it? A deceptive cadence is when a dominant (V or V7) chord moves to…A chord other than I. This are particularly striking because, as I mentioned above, the tendency tones of a dominant chord point directly to tonic. The most common deceptive cadence is V7 or V moving to vi. Here’s an example in C major:
Notice a few things: That the second chord of the example is A minor or the vi chord in C major. The second thing to notice is that that both of the tendency tones are resolved normally! Deceptive cadences are used to keep a musical idea going when it otherwise have concluded. And they sound cool.
Plagal cadences are the only cadence that doesn’t involve V or V7. A plagal cadence moves from the IV chord (called subdominant) to Tonic (I). In the key of C major that means we move from F major to C major.
A Bit of Application
Let’s return to the example we used last week: the Sor B minor etude. This is from Op 35, no. 22. The sheet music can be found here on the 10th page.
First, we have to get our tonality and key area figured out. Like mentioned above, this is in B minor. That makes our tonic chord (i) B minor and our Dominant (V or V7) F# major or F#7.
The first cadence of the piece comes at measure 8. Here we find a nice F# major chord (F# A# C#), as this is the V chord of B minor, we have a half cadence or an unfinished idea. Sor happily finishes the idea beginning in the next phrase with the same material he began the piece with. At measure 15 we find the notes F# A# and C# outlining a V chord. At measure 16 we get B D and F# outlining a tonic chord. Measure 15-16 are the closing of the idea left open in measure 8; these two measure are an authentic cadence in B minor.
The B section of the piece (starting at measure 17) begins with a B minor-ish chord and the first cadence comes at measure 24 where we find a F# A# C#. Another V chord and and a half cadence. From here, Sor departs from the nice plain sounds of before and travels through a few key areas before he closes the B section with a half cadence at measure 32 (F# A# C# E). As I mentioned above, the V7 chord wants to move back to tonic. Sor resolves this tendency at the beginning of the next phrase launching back to the material from the very beginning of the piece in measure 33. In measure 40 we get a glimpse of another half cadence (F# A# C#) which Sor quickly moves through by throwing the E (the 7th of V7) in the bass voice and drive the piece forward to the final cadence in the last two measures. In the penultimate (second to last) measure we find a huge V7 chord that resolves nicely in a perfect authentic cadence to i in the last measure.
Cadences, like any resolution of dissonance, should sound like a sigh. That is, the tense chord that wants to move, the dominant or V7 chord, should be played a bit louder then then music “relaxes” into the tonic chord which is played a bit quieter. In addition to that, cadences can be emphasized by playing with the musical time or slowing down.