I thought of something else that maybe isn't so razzle dazzle that
might be helpful.
Most blues tunes repeat a form, i.e. a specific pattern of when the
chords change (like most jazz tunes, with for the most part
different
forms between them). For blues that's predominantly what we know as
the "12 bar", referring to how many measures it takes to
complete the
form (bar = measure). Within that "12 bar" there are loads of
variations but for the most part they are fundamentally more similar
than different. That branches out to 8-bar, 24 bar, other
varieties,
but the bulk are 12-bar forms. Then there are some with a "bridge"
in addition to a 12-bar (I Want To Be Loved by Muddy). And
some with
maybe an "interlude" between verses, solos, etc. (300 Lbs., although
only the solos are strict 12-bar forms in that one). Anyway, the
deal is that most blues that we end up playing and listening to are
"12-bars" and follow a familiar form that we recognize.
In pop tunes, arguably particularly in the blues-influenced era of
the 60's and 70's (ah, wasn't that a nice time for pop music!)
familiar forms are frequently suggested or borrowed from, but not
necessarily adhered to in the classical sense. Roadhouse
blues is an
example. It's structure is such that the 24 bar form is really only
stated fully once - everything else is sort of getting there,
getting
out of it and finishing. Even though its free ranging according to
pop sensibilities, it still follows a sort of "get goin', build it
up, do it, express yourself, then suggest "it" and get out without
full repitition of form. We're used to form repeating in blues -
that's part of the style - but in pop tunes it ain't
necessarily like
that. Although nowadays the "sales through attrition" method seems
to favor a numbing repetition of material much less interesting than
our beloved blues. But then I'm a curmudgeon.
Oh cripes...I thought I'd bring something up easy and just blabbered
tons of words again. Did I mention that I drink a LOT of coffee?