What is the meaning of the song "Solid Four"?

Question

There is a song by the Andrews Sisters from the 1940s whose lyrics talk about a difference between eight-beat rhythm and four-beat rhythm. For example:

The boogie woogie was never like this,

We've got a new beat that no one can miss,

if Boogie woogie sent like I think it did,

Four to the bar will flip your lid.

I do not understand the difference, or why "Little Brown Jug" is a particularly good example of a song which is in four. I thought boogie woogie is in 4/4 time anyway? I would like examples of music which would help me to understand what two types of rhythm the song is talking about and how to hear the difference between them.

Answer 1

Like @Codeswitcher says, it's about the implied rhythm. The characteristic walking bass of a boogie woogie will imply a rhythm in eights. If you listen to Bounce me brother with a solid four, the piano in the beginning is emphasizing the quarter notes instead. You can imagine that song being played with a boogie woogie bassline to appreciate the difference.

Answer 2

Apparently the expression "eight to the bar" is the term for the "beat" (well, that's what they called it) characteristic of boogie woogie, which is actually a style of bass accompaniment. See Wikipedia's page on boogie woogie for a discussion of this and example bass lines. The "eight to the bar" means it's all in eighth notes. I'm gathering that the "solid four", in contrast, is a bass line in quarter notes. I don't get the impression that by "beat" they meant anything to do with the drum part or the meter.