Here is one of several posts in which I will provide an overview of the information at the beginning of each song post. Eventually, there will be posts about each of these concepts in depth.
Form refers to the amount and order of (usually melodic) ideas in a piece of music. It covers repetition and novelty. It is a matter of same, similar, and different.
We can look at form at the smallest levels of short ideas — the motif — to phrases, on up to large sections. Musicians usually label ideas and sections with letters. For better or worse, we only have so many ways of labeling things to show sequence and repetition. It does get a bit tricky that we are using letters for pitch and letters for ideas, numbers for keeping track of beat and meter and numbers for scale degrees and chords. Go slowly and carefully, re-read, color code — whatever it takes, if things start to get all mixed up.
I like to teach about form as soon as possible with the students in my charge. Knowing about form helps with practicing, rehearsing, composing, and improvising. When practicing, knowing what parts are the same or similar makes learning the piece more manageable; you might only be learning, say, four different ideas that are spread out over three minutes. When rehearsing, you can indicate what parts need more work (or less!). When composing, it becomes clear that you only need a few ideas balanced between same, similar, and different. When improvising, knowing the form helps you keep track of where you are and what you are doing.
For now, I will discuss some basic common forms that have their own names and will discuss more of the nitty gritty of motives and phrases and letter-labels in a different post. Because we deal primarily with songs here (less so dance pieces or other classical forms), there are a few standard terms musicians use to talk about song forms.
Verse
A verse is simply a discrete section of lyrics. Strophic songs have the same melody for each section of lyrics; there are only verses. In some ways this makes writing a strophic song easy: you only have to come up with one melody! In other ways, it's challenging: the melody has to fit the mood of the song, even as the words change. This form is common for ballads, in the original sense of the word, a song that tells a story. Sometimes that story is about love found or lost or unrequited, which is partly why now ballad often refers to a slow love song. Having the same melody over and over emphasizes the words and the general mood of the song, instead of having music that changes as the moods change.
Refrain/Chorus
Refrain and chorus are often used interchangeably, but technically there is a difference. [At least in English, there is a difference. In some languages, they only have the word refrain.] A refrain is one or two lines of text that recur at the end of each section. A chorus is a discrete section, usually with a different melody, and the original idea was that everyone joined in, you know, like a chorus.
In the chart at the beginning of each song post, if a song has verses and a chorus, then I simply label it as verse-chorus; but it might be that there are two verses and then a chorus. I'm using it as a general label about what kinds of sections and their functions there are, instead of a precise map of the form. I will eventually make a set of indices categorizing songs by their form.
A few other forms we encounter:
Interlude/Ritornello
Some songs have instrumental sections. If the instrumental section is a fixed melody that comes back after each verse or after each verse-chorus pair, that is a ritornello (That's Italian for little bit that returns). If the instrumental section is just a phrase or two of background or maybe with a riff (a short, repeated melody), that is an interlude. If the instrumental section features a solo instrument (improvising or not), that's a solo — but sometimes I call that an interlude, too. Interlude is Latin for play between (it's the same in Czech — mezihra), so a solo is really just a type of long interlude. I suppose so is a ritornello, but a ritornello often comes at the beginning as well.
Bridge
A bridge, technically, is a brief visit to a new tonic. I often see things marked as a bridge that are not really bridges since they lack the new tonic. Since we are working with only two chords, there are too few harmonies to really establish a new tonic, unless you have a song where everything else is on one chord. All this is to say, we won't be hearing bridges for the most part (the only thing that mostly qualifies is Can I Kick It, but really, that should be labelled an interlude, so I should change that).
Breakdown
A breakdown has the same harmonic progression as the verse or chorus, but with fewer elements: many instruments drop out, perhaps there are no lyrics — there are several ways to pull this off.
Intro/Outro
Sometimes there is a discrete section at the beginning or end of the song.
Call & Response
This is a compositional structure that has elements of both form and texture (the relationship between the density of the background parts and the melody — a whole other post!). Call and response involves the alternation between a solo voice singing a phrase and a group responding with the same thing or its own phrase.