I listened to Tales of Mystery and Imagination earlier and noticed something about "The Tell-Tale Heart." Even before I started this project, I noticed that the ternary structure of the song mirrors the mental state of the narrator. In the first section, the narrator is paranoid because of the old man's eye, and to reflect this, there's the standard rock song instrumentation of guitar, bass, and drums, along with a raucous vocal. In the middle section, after the narrator has killed the old man, he calms down. The instrumentation becomes lighter (with strings and woodwinds), and the vocal is smoother. Once the narrator starts to hear the old man's heart beating again, he becomes distraught, and the instrumentation returns to what it was in the first section.
Listening to the song this evening, I noticed that this change in mental state is also illustrated in the rhyme scheme. For the most part, the first and third sections have an ABCB rhyme scheme; the sounds at the end of each line bounce around in the same manner as the narrator's addled mind. In the second section, however, the rhyme scheme is AAA; it's stable and consistent, as if the narrator has found peace of mind.
