Free verse always sounds so light and liberated and... well... free. But don't be fooled. While Giovanni doesn't have to abide by a strict formula for meter and rhyme, she has to use other devices to make her poem sing.
In this case, she uses enjambment to keep her lines flowing (if you listen to her perform her poem "Nikki Rosa," you'll see how breathless and quick her pacing really is). The lack of punctuation also steps up the momentum of her lines. Take a look at stanza 1 for a good example of this technique at its finest:
We sat on the front porches watching
The jfg sign go on and off greeting
The neighbors, discussion the political
Situation congratulating the preacher
On his sermon (3-7)
At the end of each line, we as readers are urgently propelled onto the next one.
Giovanni also uses repetition—of phrases and sounds—to create the signature rhythm and swing that imitates natural speech and storytelling. You can see this at work in stanza 3 with a type of repetition called epistrophe: "Mrs. Long always glad to see you/ The stereoscope always ready to show you" (24-25).
In addition to this rhythmic repetition, Giovanni changes up both stanza and line length to create a variety of cadences in the poem. If you scan the poem with your eye, you'll probably be able to pick out two unusual moments: stanza 5 and stanza 8. Stanza 5 is the only two-line stanza in the poem and it packs a huge emotional punch: "Probably they said something humiliating since southern/ Whites like to humiliate southern blacks" (31-32). Ouch.
Stanza 8 has a series of one- and two-word lines, giving a quick, staccato feel to the ending of the poem. This allows Giovanni (and us) to place emphasis on each of those words, slowing the poem to a halt and letting the true worth of Mrs. Long set in.
Apart from the structure of the poem itself, Giovanni has a ton of sounds popping off in her lines. For that, you should take a look at our "Sound Check" section.