How is an "eight-bar blues" different from just eight normal measures of music?

Question

Just about everyone knows the twelve-bar blues, a common example of which would be something like:

I  | I  | I | I |
IV | IV | I | I |
V  | IV | I | I ||

I completely understand how this can be stretched to create a sixteen-bar blues. In Elvis Presley's "Jailhouse Rock," for instance, the chord progression is clearly an elongation of a normal twelve-bar blues; it has the stereotypical V–IV motion at the end, just with an added four measures of tonic in the second grouping of four measures:

I  | I  | I | I |
I  | I  | I | I |  <-- insertion
IV | IV | I | I | 
V  | IV | I | I ||

My confusion comes in identifying the so-called "eight-bar blues." Wikipedia cites Elvis Presley's "Heartbreak Hotel" as an example:

I  | I  | I | I |
IV | IV | V | I ||

But what makes this specifically an eight-bar blues as opposed to just a normal eight-measure chord progression? I know that the text is of the common downtrodden nature of a blues, but surely this doesn't mean that every eight measures of sad music constitute an eight-bar blues.

The only other stipulation I can imagine is the famous call-and-response opening of the blues style. But Wikipedia cites "Tain't Nobody's Biz-ness if I Do" as an early eight-bar blues form, yet I don't hear the standard call-and-response lyrics here.

Answer 1

I think a large part of what makes a blues progression a 'blues' progression is the use of blues tonality - most typically, the use of the 7th chord as a characteristic color on I, IV and V - not just on V.

Looking at Heartbreak Hotel...

I | I | I | I

Er... Where's the 7th? To my ear, it's in the melody - Elvis really leans on that flat seventh in the delivery (bending it in archetypal blues style), making it distinctly different from other 'straight major' songs. This is an example of how the use of the blues scale in the melody can actually make a difference to the tonality, and to how the progression is perceived.

Answer 2

But what makes this specifically an eight-bar blues as opposed to just a normal eight-measure chord progression?

We're talking about classifying a cultural artifact, so in addition to physical measurements of the artifact, you need to take into account the where, when, who of it. Where was this artifact found? Who made it?

The music arose in a blues-based culture, and therefore it is looked at as blues. If you had found the structure in a culture where nobody had ever had any interactions with anyone who knew about blues, then you probably wouldn't look at it as a product of blues music.

Quote from the Wikipedia page https://en.wikipedia.org/wiki/Eight-bar_blues

In music, an eight-bar blues is a common blues chord progression. Music writers have described it as "the second most common blues form" being "common to folk, rock, and jazz forms of the blues".

The blues has to be understood as a culture, not a mathematical formula for describing a class of structures. Within the context of blues music, there are several structural variations like 12-bar blues and 8-bar blues.

Answer 3

I have a feeeling that the format isn't that much of a guide. There are plenty of examples of 12 bar Blues formats that wouldn't be classified as blues. Just because the pattern fits doesn't guarantee they'll be Blues.I guess that 12 bar pattern was round way before blues were discovered/invented.

So, the same applies to 8 (or 16 - or other) bar Blues. It's what else goes on that signifies which category they get put into. Obviously use of the Blues scale, and Blues idiom are of great importance - and I even wonder if a particular song can still be classified as Blues - even when its format isn't 8 or 12 bars, even. Course it can!

Answer 4

Note that every single eight-bar blues chord progression in the Wikipedia eight-bar blues article you cited has a I chord of some sort before at least one IV chord of some sort - all but one of those chord progressions has a I chord of some sort in Bar 1 - and every single eight-bar blues chord progression in that article has a IV chord of some sort in at least one of Bar 3, 5, and 6.

From previous listening experience, it is the movement from I to IV (or tonic to subdominant) that characterizes the eight-bar blues. Heck, I detect blues influence in popular music-leaning works (e.g. jazz, various third stream and fusion, concert band, even metal) if I hear any chord progression hovering around the tonic for long enough immediately followed by any chord progression hovering around the subdominant.

Answer 5

For a start, it's not I, IV and V, it's I7, IV7 and V7 - even if the m7ths are largely in the vocals until the instrumental chorus.

Why a 'blues'? Well, there are many points of similarity with the classic 12-bar blues. 4 bars of I7, then IV7 and V7 leading back to I7.

Interesting how many printed editions get it wildly wrong, both melody and chords.

Answer 6

The song called "Choko Mo Feel No Hey" is an example of an 8 bar blues. It's like a riff which is repeated every 8 bar the whole song. I've found this structure to be really rare. As dancer i don't hear any "B" phrases, this differes from other 32 bar swing/jazz structures.