Sometimes lyricists just give up before finishing the job. Paul Simon for example in “The Boxer” left some filler lyrics in the final version of the song, “Li li li, li li li li li li li…”, because he felt lazy, or because he couldn’t think of real lyrics, or because he thought the song was good enough as is, or because—well, no one really knows, not even Simon, why the “Li li li” lyrics are in there, and no one really much cares. It’s a terrific song, so what am I complaining about?
Well, we have the time, don’t we, to finish the song? Sure we do. So take a stab at it.
Find some appropriate, fitting lyrics to “The Boxer” that comport with the meter of the “li li li” part, and improve the song.
Or you could do the same with Paul McCartney’s filler lyrics at the end of “Hey Jude,” another megahit that succeeded (I argue) despite the lyricist deciding to go with the filler “Na na na, nana na na” instead of supplying a real chorus at the end. Have a go at it.
I suspect, myself, that the motivation for these (and other) filler lyrics was simply frustration. A songwriter often begins with a melody, and composes a song with 100% filler lyrics, and slowly wrenches a word, a phrase, a line, a quatrain to fit the tune, and works out the orchestration and harmonies before writing very many lyrics down. By the time he’s figured out the music and 50% of the lyrics, he’s probably sick of the song, and if he works on it further and finds that he’s still got 10% of the lyrics to go, sometimes he just decides “Hell with it, I’ll just go with La la las” and hope no one notices. Maybe sometimes he comes up with that final 10% and dubs it into the recording.
I got this idea by listening to the Grass Roots’ “Live for Today,” which features another filler device, counting the beat aloud before going into the chorus: “One, two, three, four! Sha la la la la la, Live for today…” Surely you guys can come up with better lyrics than that.