A fun article from Atlas Obscura explaining the “it’s gonna be may” meme:
It’s not super fun to explain a meme, but we kind of have to, so: The “it’s gonna be may” meme is a reference to NSYNC’s 2000 hit “It’s Gonna Be Me,” in which lead singer Timberlake memorably sings the title of the song as “it’s gonna be may.” But I think what makes the meme resonate is that “it’s gonna be may” is just one example of a linguistic tendency that was weirdly popular in the late 1990s and early 2000s.
Think of Mandy Moore’s “Can-day,” Britney Spears growling “oh bay-bay bay-bay,” Gwen Stefani chanting “hey bay-bay hey bay-bay HEY.” The trend to turn the “ee” sound into “ay” continued for years, maybe most memorably in Gnarls Barkley’s “Crazy.” (Cray-zay, really.) This isn’t one guy’s vocal quirk: this is a trend, maybe a virus. Why did all these singers change their vowels in that particular way? […]
Except, most of those examples, especially “it’s gonna be may” and “canday,” aren’t especially high notes for Justin Timberlake or Mandy Moore. They aren’t actually straining to hit them. So why are they acting like they are?
Lewis’s theory, which makes sense to me, is that this is an attempt to co-opt the signifiers of intensity without actually needing to use them. Wonder sings “baybay” late in “Superstition” because he’s worked his energy level up, he’s hitting a high, hard note, it bursts out naturally because that’s the way it’s comfortable for him to sing it. “It’s gonna be may” is not like that; Timberlake could sing a clean “me” there perfectly comfortably. But listeners like the intensity of lines like Wonder’s; it’s big and bold and passionate. And Wonder’s vowel sound there has come to indicate to listeners that he’s being big and bold and passionate. Timberlake, Moore, and Spears all just…use that signifier, without any of the physiological need for it. It’s fake energy. Fake passion.
See also these articles about the linguistics of indie pop voice and pop punk voice.