MUSICAL FORM

Now that we are starting to grasp both melody and harmony, how to properly voice lead, and where to find different chords and inversions in the time and space of music, we can now put these elements together to begin studying complete musical phrases. To do so, we will use our knowledge of tonal areas and the new concepts of cadences, phrases, and periods, to analyze and compose simple melodies.

MUSICAL FORM is the structure of phrases within a larger piece of music. To discover or create musical form, identify the length of phrases and periods by finding rhythmic pauses or important moments and repetition. Consider cadence types, weak and strong areas, and glean a birds eye view of large sections.

CADENCE

In music, a CADENCE occurs at the end of a musical phrase, serving as a resolution or pause point in the larger piece. It is similar to the way we use punctuation in written language. Just like a period “.” or a comma “,” or an exclamation mark “!” or a question mark “?” or an interrobang “?!” can help to bring the right energy to a sentence or phrase, so too, do cadences with phrases of music. In general, cadences are the interaction of the penultimate and final chords in a phrase within the context of the overall key of the piece (or section of the piece). The following are the most oft-used cadences …

PERFECT AUTHENTIC CADENCE | PAC | V - I

The PERFECT AUTHENTIC CADENCE is the strongest of all cadences and occurs most often at the end of a complete piece of music or at the end of large sections of music (but can, of course, occur elsewhere). It moves from Dominant area to Tonic area very directly. To be considered a PAC, the cadence must have both a specific two-chord progression and a specific melodic motion which is not required of other cadence types. The PAC must move from a root position V or V⁷ to a root position I chord. In the melody (soprano voice), it must follow a stepwise melodic contour above the V - I motion of scale degree 2 - 1 or scale degree 7 - 1.

IMPERFECT AUTHENTIC CADENCE | IAC | Vˣ or viiᵒˣ - Iˣ

The IMPERFECT AUTHENTIC CADENCE is a way to move from Dominant to Tonic area in a weaker way which is a good technique when you want the harmony to move to Tonic but not feel like your longer idea is over. An IAC will be any Authentic Cadence that doesn’t follow the strict rules of the PAC above. This could include moving from a V - I chord with either or both chords in inversion or a viiᵒ - I chord with either or both chords in inversion or the melody not moving from 2 - 1 or 7 - 1 or a combination of both.

HALF CADENCE | HC | ? - V

The HALF CADENCE is the musical phrase equivalent to a question mark or a comma in a written sentence. An HC completes the phrase in dominant, making the phrase feel not only incomplete and unresolved, but leaving it in the dominant area specifically adds tension to the point where your ear can only be satisfied by hearing another phrase that provides the answer. Half Cadences always finish on a V but can come from any chord before it. Most often, it will come from a Tonic area or Predominant area before moving to Dominant on this final V chord.

PLAGAL CADENCE | PC | IV - I

The PLAGAL CADENCE is also known as the “Amen Cadence” because of its prevalence as the final cadence in many Christian church hymns. The PC is the movement of a IV chord to a I chord. This cadence type skips the Dominant area altogether, moving straight from Predominant to Tonic. However, many times this cadence is used as a “follow-up” to a previous V - I cadence set-up. The PC is much weaker than the PAC or IAC because the IV is lacking a leading tone. Without the leading tone or time in the Dominant area, the resolution to Tonic is not as strong or satisfying.

DECEPTIVE CADENCE | DC | V - ?

The DECEPTIVE CADENCE, sometimes referred to as the Interrupted Cadence, is a cadence that deceives our ears by making us think we are about to hear an Authentic (V - I) Cadence. Instead, the Dominant V chord will cadence on any other chord besides I resulting in a “surprise ending.” The chord V most often moves to instead if I is the minor vi chord. This chord works well in this place because there is still a first scale degree in the vi chord and the resulting effect is a moment of minor when your ear expected major.

We also know that while a vi chord is most often found in the Predominant Area, it can function as a TONIC SUBSTITUTION, especially in first inversion when the chordal 3rd (which is the 1 of the scale) is in the bass.

STRUCTURE

PHRASE

A musical PHRASE is a self-contained musical event ending in a cadence. It doesn’t need to be a complete, fully-fleshed idea, but even, just like in writing, the first half of a sentence before a comma.

ANTECEDENT PHRASES are phrases that feel open-ended like a musical question. They are often finishing in the Dominant area or somewhere outside of Tonic.

CONSEQUENT PHRASES are phrases that follow Antecedent Phrases and usually feel, closed - like an answer to the question. These most often finish in Tonic.

PERIOD

When an Antecedent Phrase is coupled with a Consequent Phrase in a balanced, organized way, the resulting two-phrase idea is called a PERIOD. Because much Western Classical Music relies on symmetry and balance, Periods are usually the goal when composing in a logical sequence. In fact, composing with phrases that are not in Period form have the effect of surprising your listener with more unique forms.

COMMON FORM TYPES

Phrases or Periods are often grouped together in formulaic ways which provide a level of understanding and predictability to listeners. Below are some types of form you will often encounter - especially in simpler music such as folk songs, nursery rhymes, pop tunes, and basic pieces from the Baroque and Classical eras of Western Music.

For each form, the first section (which could be a singular Phrase but is most often a complete Period) is labeled as “A” and any direct repeat of that phrase would also be called “A.” When a new section of music is presented, it is labeled with the next letter of the alphabet: B, C, D, etc.

If a section of music appears that is almost identical to a previous section but is slightly different - perhaps a few different notes in the melody, or a slightly different harmonic progression (especially the Cadence), then that new section will receive the same alphabet label and an apostrophe - ‘. So a section almost identical to A is A’, almost identical to B is B’. If you already encountered an A’ earlier in the piece and you are presented with yet a third new version, it would be labeled A”. When speaking about these sections, the apostrophe is called PRIME. So you are labeling the sections “A,” “A Prime,” “B,” “B Prime,” “A Double Prime,” etc.

PRACTICE …

Download the following sheet from this page or from our Canvas site to help keep track of the new form definitions and practice identifying form with a given melody. To do so, play the melody on a piano or sight sing it. Decide its key signature and then what chords fit into that key (especially I - Tonic, IV - Predominant, and V - Dominant). Using the scale degrees, determine which diatonic chord fits best under each measure. Decide where phrases start and stop (the first phrase will begin on the first measure - but where will it end? How long is each phrase? How many total?) When you decide where a phrase ends, then look at the last last two chords of the phrase and determine the cadence type for that phrase: PAC, IAC, HC, PC, or DC. Follow along with the video below to check your own answers or receive guided instruction as you complete the worksheet.