Use of "them" as an article, not a pronoun

I've seen a lot of times the pronoun them used like an article. For example, in the title of the Delta Rhythm Boys Them bones, or in the first sentence of "Money for nothing":

Now look at them yo-yo's, that's the way you do it.

I know that it's not "proper English" (i.e., not something you'll use in a serious writing), but I'd like to know when it's commonly used, and why. Is there any difference between using it and using the?

It's a non-standard
(although perfectly valid within the context of a valid personal and location based free choice in the subset of English which one chooses to consider valid within one's own frame of reference)
use of 'those' - I think it's also an American dialect/regional variation

In African-American Vernacular English (AAVE) them often replaces those, or less often, the article the. Due to hip-hop culture having developed with heavy African-American influence, rap lyrics are often in AAVE.

Although possibly unrelated, them is also used in this way in Appalachian English.