I'm analyzing blues in the Mississippi Delta tradition and the hardest/most subjective aspect I am running into has to do with songs with measure numbers divisible by 8. For example, we can use "Death Don't Have No Mercy," by Reverend Gary Davis. Depending on how I define the measure and the time signature, each verse either fits the AA'BA pattern of the 32-bar form or a 16-bar blues. I will briefly write out the chord progression for reference:
|Em -|Am B|Em -|Em -| |G -|A7 D7|G -|B7 -| |Em -|Em -|Am -|C7 -| |Em -|C7B7 Em|Em -|Em -| |i -|iv V|i -|i -| |III -|IV7 VII7|III -|V7 -| |i -|i -|iv -|VI7 -| |i -|VI7V7 i|i -|i -|
As you can see, the way I have defined the measure and time signature, this verse fits as a 16-bar blues. But in that 14th bar, there's a chord change within a single beat. That one measure kinda makes me want to subdivide the whole thing again and call it a 32-bar blues. Each line would therefore become 8 measures, that C7 and B7 would get their own beats, and the verse would fit the AABA melodic pattern characteristic of a 32-bar sequence. So, how do I resolve the subjectivity of time measures? How do I classify this song in a way that will be consistent with other analysts?