Which pop song repeats a single phrase the most number of times? I thought about this question after hearing Green Day's "Boulevard of Broken Dreams," in which Billie Joe seems to keep running out of things to say so he just decides to say "I walk alone" one more time. If the lyrics I found online are correct, and I make no claims that they are, the phrase "I walk alone" repeats in that song 14 times. An impressive amount, but by no means a record.
The song that people usually think of in regards to this question is the Trashmen's brilliant "Surfin' Bird," an agglomeration of two earlier Rivingtons songs ("Papa Oom-Mow-Mow" and "Bird Is the Word") that went to Number Four back in 1964. Pee Wee Herman's cover, from the 1987 film Back to the Beach, inexplicably failed to chart. Nevertheless, the song repeats the phrase "Bird is the word," by my count, 21 times.
That's only tied for third on my little survey, though, with the Rolling Stones' "She's So Cold," which repeats the title phrase 21 times. It's pretty much the same idea as "Shattered," though not nearly as good, but "Shattered" falls outside the parameters of my research, since the title is a single word, and I don't want to get started counting how many times a single word appears in a song.
"Hey Jude" repeats its own title 26 times: seven times during the main body of the song, and 19 times during the extended codas.
Michael Jackson's "Smooth Criminal" far outdistances that, using the phrase "Are you okay" - either in the form "Annie, are you OK" or "Are you OK, Annie" - a whopping 40 times. Until I researched this post, I thought he was saying "Eddie, are you OK," which suggests that maybe Michael should have repeated the phrase a few more times for clarity. Or rather, that he should have used the phrase fewer times, rendering the song less annoying and me more likely to listen to it closely.
Near as I can tell, for a song that made the pop charts, that's the record, although I assume it shares that distinction with the cover by Alien Ant Farm.