After the frenzy of comments offering up various songs in which various phrases were repeated great numbers of times, I can compile the following scoreboard, sorting out the current leaders by number of words per phrase (and thanks to the poster known as Scraps, which I suspect is not his real name, for suggesting that particular taxonomy for this project).
I do want to take a moment to thank everyone who contributed to this project, and if you just tried to think of a repetitive song but couldn't beat any of the prior offerings, you still participated, and I still thank you. At its best, writing OPC is like hosting a party, and this was the best party yet.
My initial inclination was to limit this to Top Forty hits, since no one wants to count how many times Kraftwerk say "Tour de France" in the six-and-a-half-minute version of "Tour de France." But there were plenty of songs suggested that are familiar radio favorites without ever being Top Forty hits:
Two words: "I Can't Stand Losing You," by the Police, for "I can't": 70 times. At a running time of 3:10, that's approximately one "I can't" every pi seconds. The amazing thing is that song never gets annoying, despite the fact that there's a phrase repeated three score and ten times, and despite Sting's legendary capacity to annoy.
Limiting it to the Top Forty would have made the winner "Beat It," by Michael Jackson, for "beat it": 56 times, or maybe even more. I counted 67, but it's awfully hard to count, especially the part where Michael's saying "Beat it," and it's repeated as an echo three or four times. Whether those count or not is at the discretion of the listener, but clearly, no one wants to be defeated. Also, Eddie Van Halen can play that guitar just like a-ringin' a bell.
Three words: "Take a Chance on Me," Abba, for "take a chance": God only knows how many times. I counted Agnetha and Frida singing it 15 times, and Benny and Bjorn singing it 109 times, which would make 124, except that total is almost certainly wrong. The problem is not just that the guys are chanting "Take a chance/Take a chance/Take a chance" very quickly through much of the song, but that their backing vocal gets buried in the mix, and it's hard to hear sometimes whether they're still singing it. If anyone is technologically adept enough to strip out the backing vocals on this record so they can be heard clearly enough to be counted, be my guest. All I know is that this is the winner.
Four words: "Taking Care of Business," Bachman-Turner Overdrive, for "taking care of business": 27 times. Of all the songs on this list, this is probably the easiest one to beat. Technically, I guess the next two songs beat it, with the phrases "why can't we be" and "boys are back in."
Five words: "Why Can't We Be Friends," War, for "why can't we be friends": 47 times.
Six words: "The Boys Are Back in Town," Thin Lizzy, for "the boys are back in town": 26 times.
Seven words: No entries so far. What's wrong with you guys?
Eight words: "Voices Carry," Til Tuesday, for "hush hush, keep it down now, voices carry": 19 times
Nine words: "Next to You," the Police, for "all I want is to be next to you": 15 times. Reader MJN suggested the nine-word phrase was repeated 27 times, but I listened again to the song and got only 15, which is still the leader in the category, alongside "Never Say Never" by Romeo Void, which repeats "I might like you better if we slept together" 15 times. Maybe MJN listened to it twice.
Neither of those songs cracked the Top Forty; the Top Forty leader I have is "It's Only Rock 'n Roll (But I Like It)," by the Rolling Stones, which repeats the title phrase either 12 times or 25, if Keith is actually saying "It's only rock 'n roll" each time on the outro, although mostly it sounds more like " 's only rock 'n roll" or "only rock 'n roll." It's too late here for me to listen to it again.
Ten words: "It's the End of the World As We Know It," R.E.M., for "it's the end of the world as we know it": 22 times
Fourteen words: "I Want to Know What Love Is," Foreigner, for "I want to know what love is, I want you to show me": 7 times
Sixty-six words: "Out of My Head," Fastball, for "Was I out of my head? Was I out of my mind?/How could I have ever been so blind?/I was waiting for an indication/It was hard to find/Don't matter what I say, only what I do/I never mean to do bad things to you/So quiet but I finally woke up/If you're sad, then it's time you spoke up too": three times