Following are notational conventions for analyses of musical form.
Modules are labeled with capital letters according to function. A module that functions as a strophe is labeled with an “A”; a module that functions as a bridge, “B”; etc.
Phrases are labeled with lower-case letters according to their musical content. If two phrases use more-or-less the same musical framework (harmony, melody, and rhythm), they receive the same letter. Letters are assigned in the same manner as poetic rhymes: the first phrase is a and any phrase that follows based on the same music is also a (primes are used for slight variations, such as new text or altered instrumentation); the next phrase with new musical material is b; and so on. These letters do not correspond to functions.
The single exception to this convention is when phrases within a module demonstrate a sentential progression (srdc), in which case the first phrase (statement) is labeled s; restatement/response, r; departure, d; conclusion, c.
Full-sized numerals are attached to capital letters when there are two or more modules with the same function but different music. For example, if a song contains two different melodies that both function as verse themes, they are labeled “V1” (the one that appears first in the song) and “V2.”
Subscript numerals are attached to capital letters when there are two or more modules with the same function and music but different text. For example, if a song contains three verses, and they all have different lyrics but the same music, they are labeled “V1”, “V2”, and “V3”.