The melody of the song should be natural, flowing like a river. Yes, it can have little whirlpools, rapids, and even waterfalls. But only as inserts. If your song is a continuous transition from bass to falsetto, it will be unpleasant and unaccustomed to the ear. And vice versa, monotonous as a swampy plain - the song will be boring and not interesting to anyone. Usually the choruses act as waterfalls that catch the listener's attention.
Choruses just can be tearing, with fragments of phrases, giving more emotion than meaning. Moving on to practical advice - try to compose a verse of eight lines, describing the situation, setting the plot. And after that, 4 lines of the chorus, describing your attitude toward the object described in the verse.
Here's an example. One of my songs has lines like this:
When I woke up you were already gone
Seems like it's every day
You never wanted to stay
Before the night is turning into dawn
And if i don't die today
Is up to you
Even though i'll miss you badly
I don't want to argue
Lost in memories
Looking so good to me baby
But i'll find my sunrise
I wonder maybe
A reckless fire in the pouring rain
So many nights like this
Why is this world so gloomy
Come on, go down the sleepy subway train
Live all your fantasies
We've got to live for today
Here in the verses I write on behalf of an unhappy lover who is unrequitedly in love with his girlfriend. The first six lines are enough to establish a vector of understanding. In the chorus, the narrator speaks directly to his girlfriend, emotionally coloring the overall narrative.
A really popular song is the one that touches the heartstrings of as many listeners as possible. But if it is a simple description of the situation-the author deliberately narrows the audience to those few who have lived similar moments in life. And it is the refrain that pushes the boundaries, gives out the emotion (for example) of doom, melancholy and hopelessness, which, unfortunately, is characteristic of almost all people at one time or another in their lives.
Touching a little on the separate topic of the melody of the song, I note that the music (for example, in a solo) should not fly between octaves either. Understand the important point - the brain likes the melody, which can be reproduced by the vocal chords. It is this simple rule that turns an unpretentious melody into a popular hook that sits in your head and is sung by generations of listeners - popular guitar riffs of famous rock bands, for example.
In the next post, I'll explore the subject of flow. Where I'll show by example the importance of forming lines with rhymes, stressed syllables, and also hints, for example, where the same word is the end of one line and the beginning of another one. This is exactly what I applied in the song mentioned in the current post.
Listen to how it sounds. It's very interesting to hear your comments. Subscribe to the youtube channel and write your feedback, as well as suggestions about what you are interested in learning about songwriting.