Disclaimer 1: I am not a lyricist, nor have any training in the field. However, I am a composer, and have a good understanding of repetition as it applies to instrumental music.
Disclaimer 2: Spoilers ahead for Moana and Beauty and the Beast.
For the sake of simplicity, repetition refers to both repetition and imitation, or exact repetition and variations of motifs.
Repetition is one of the biggest ways to emphasize a point in various mediums, including music. In an instrumental piece, a composer would repeat motifs, and it would be these motifs that the listeners remember – for instance, the DUN DUN DUN DUUUUN motif in Beethoven’s Fifth Symphony is the most repeated, and therefore the most remembered.
Recently, while obsessively playing Disney songs on repeat, I started to notice that Disney tends to use repetition in the lyrics of different songs to show character and plot development.
For instance, in the newest animated Disney movie Moana, this repetition happens in “Where You Are” and “I Am Moana”. In the first, and opening, song, the grandma gives Moana this advice (emphasis mine):
“You are your father’s daughter
Stubbornness and pride
Mind what he says but remember
You may hear a voice inside
And if the voice starts to whisper
To follow the farthest star
Moana, that voice inside is who you are”
Later, when the grandma is giving encouragement to the discouraged Moana in “I Am Moana”, she says:
“The people you love will change you
The things you have learned will guide you
And nothing on earth can silence
The quiet voice still inside you
And when that voice starts to whisper
Moana, you’ve come so far
Do you know who you are?”
The repetition in the second song brings to the audience’s memory the first, and the differences in the lyrics show the character development in throughout the movie. In the first song, the grandma is giving direct advice, whereas in the second song is more open-ended. By that point in the movie, Moana is passed needing advice, and instead just needs a nudge to gain her back her confidence in herself and stop believing that Maui (who had just stormed off angrily) was the only one who could restore the heart.
Also, the voice inside is a major motif throughout the entire movie, not to mention part of the reason why Moana stands out from other Disney princesses/women. The know who you are motif reappears in the climax, when Moana restores the heart.
In Beauty and the Beast, the songs “Belle” and “Something There” use a similar technique. In the bridge-type portion of the opening song “Belle”, Belle sings (emphasis mine):
“Oh, isn’t it amazing?
It’s my favorite part because you see
Here’s where she meets Prince Charming
But she won’t discover that it’s him til chapter three”
In “Something There”, the song that narrates Belle and Beast growing close, she sings to the same melody:
“New and a bit alarming
Who’d have ever thought?
True that he’s no Prince Charming
But there’s something in him that I simply didn’t see”
The parallel melody and lyrics show how Belle was experiencing in “Something There” the same type of thing she was reading in “Belle”. In fact, some, like the SuperCarlinBrothers, have said that Belle was reading her own story when she sung that verse in “Belle.”
In the non-musical musical world, the same technique can be seen. in Fun.’s song “Carry On” they use this technique in the first pre-chorus and the bridge. The pre-chorus goes (emphasis is still mine):
“You swore and said we are not
We are not shining stars
This I know
I never said we are”
Through the middle of the song, the energy builds, and the bridge mirrors the first pre-chorus with:
“Cause here we are
We are shining stars
We are invincible
We are who we are”
The negative line “We are not shining stars” turning into the uplifting “We are shining stars” in the bridge follows the general flow of the song. The beginning is depressing, but as the song goes on it becomes more upbeat and uplifting, much like “I Am Moana” does in the previous example (why do I feel like I just compared apples and oranges?).
Basically, the use of parallel melodies and lyrics help show the character and plot development in a very interesting but subtle way.
Image from Wikipedia