Okay. So. Cadences.
Where to start. In short: Cadences are like the commas and full stops of music. They are phrases of chord patterns that give music a sense of either needing to move on, or needing to stop.
At the end of a passage of music, you might notice that the music itself feels like it needs to finish. This is what the cadence does.
Feel free to bash all of this out on a piano as you go along. In fact, I encourage it.
I suppose we'd better go back over degrees of the scale. In music, we use the Roman numerals to indicate the position of a chord in a scale. Major chords use upper case and minor (and diminished) chords use lower. I'm going to stick with C major all the way unless I say otherwise.
C - I Dm - ii Em - iii F - IV G - V Am - vi Bdim - vii
(Just need to mention, I think cadences are one of the areas where the names of shit are different in the US from England. I'll teach you what I know and hope it holds.)
The four main cadences you'll come across are:
Perfect
Imperfect
Plagal
Interrupted
Two of these are 'comma' cadences and two of them are 'stop' cadences. The ones you;ll come across most often are perfect and imperfect.
Perfect cadences are designed to END a piece or a phrase. They use the chords IV-V-I (Or in C major: F-G-C). The V chord can be replaced with V7 and it still works.
Imperfect cadences (also called a half-cadence) use the same chords in a different order. They are designed to make a piece feel like it's pausing in the middle before needing to move on. They use the chords IV-I-V.
Plagal cadences (also known as the 'Amen' cadence) are another 'stop' type. They use x-IV-I instead of x-V-I, where x is pretty much any chord ever. Typically it'll use the sub-dominant relative minor, which makes it ii-IV-I.
Interrupted cadences start out sounding like perfect, and then switch to go somewhere else at the last second just to catch you out. It's pretty much anything to V and then V to anything other than I, usually vi. Oh and the V is actually more likely to be V7. This cadence is a particular menace. Its usual form is ii-V7-vi or IV-V7-vi, but its pretty much just as likely to be something else entirely. Slippery little bastard.
I HOPE THIS EXPLAINS CADENCES it probably doesn't at all omg im so sorry
Whatever you do, don't try and read the wikipedia page. That thing is a minefield of confusing musical terminology that even I can only barely decipher.
There are also a whole bunch of other cadences that crop up like phrygians and inverteds and lydians but it's best to just avoid them like the plague. Things are bad enough as it is.
jesus christ cadances you need to slow down
i think i mostly understand it tho, except V7?? what??
