When we sing along with a song on the radio, sometimes we sing the wrong words. Often the mistakes are funny: "Scuse me while I kiss this guy" or "There's a bathroom on the right." Errors, like these funny song lyrics, provide insights about how people construct their perceptions and reconstruct their memories.
By the way, "Scuse me while I kiss this guy" was originally "Scuse me while I kiss the sky" in the version of the song that Jimi Hendrix wrote and performed. "There's a bathroom on the right" was "There's a bad moon on the rise" by Credance Clearwater Revival. Although I've always know the correct version of Bad Moon, I enjoyed singing about the location of the bathroom (particularly when I was singing along with the song at a loud party). John Fogerty (CCR's singer) has also occasionally slipped in the bathroom version in live performances. By the way, an entire website is devoted to misheard and misremembered song lyrics and it's called, appropriately enough, Kiss this Guy. You can even provide your own examples.
In my first research project, I investigated memory for Beatles song lyrics. Generally if people remember a line, they remember it perfectly. This might lead you to think that people have songs memorized verbatim.
But the errors tell a different story. The errors provide a window into the constructive nature of perception and memory. Most errors that people make are very reasonable. The changes almost invariably maintain the rhythm, poetic, and meaning patterns of the song. For example, consider this line from the song Lady Madonna by the Beatles: Lady Madonna, baby at your breast, wonder how you manage to feed the rest. When David Rubin and I asked people to remember this song, one person wrote: Lady Madonna, baby at your breast, wonder how you manage to be caressed. (Of all the errors we collected, this was always Rubin's favorite.) The new version held consistent the rhythm and poetic pattern of the line. In the context of the entire song, I think this person's rewritten lyrics make semantic sense as well.
If you know the patterns of a song, then reconstructing the song as you listen and sing along is straightforward. In nicely written songs, there are few opportunities for errors: Few words other than the original words fit the pattern of a song. You either get the right words or typically you recall nothing and simply hum the tune. In his 1995 book, David Rubin explored reconstructed lyrics in a great variety of materials, including Homeric ballads, North Carolina traditional ballads (often with Wanda Wallace), and counting out rhymes (such as Eenie, meanie, miney, mo).
In some ways perceiving and remembering a song is just like perceiving and remembering anything else - constructive. Our schemas and general knowledge structures guide our expectations, perceptions, thoughts, and memories. Songs lead to more consistency because there are multiple constraints that guide cognition. In most situations, only the meaning constrains how you reconstruct your memory. Thus you can remember the basic idea of what someone said but may experience difficulty remembering the exact words. But in songs, meaning, rhythm, and poetic patterns constrain your reconstruction. For example, in the final line of Rocky Raccoon (another Beatles song), there are few endings that provide a sensible solution. For the last word, you need three syllables, at least a soft rhyme with Bible, and something that expresses how the bible will help Rocky considering that he has just been shot. I think only revival and survival will fit. One is the original version and the other is the single error Rubin and I observed in this line when people were remembering the song. We remember the correct words many times because the patterns of a song are so tightly constrained that only the original words will work.
Of course there are times in popular music when the lack of clarity in the recording can lead you to construct the wrong meaning and the wrong words. I knew someone who told me that she liked early REM songs because you couldn't understand the lyrics and had to make up your own. Our memories of a song are always a mixture of what is in the song and the constructive guidance we draw from the overall patterns. Our constructions of reality are the same - a mixture of what is in the world and schematic guidance from our general knowledge.