Why would singers omit 's' from "He takes/makes/etc" in song lyrics?

I heard it done on purpose in different songs; like here

http://www.lyricsfreak.com/m/mark+knopfler/news_20089384.html

He's burning the grass
He take up a glass
He swallow it neat

and here

http://www.azlyrics.com/lyrics/johnfogerty/theoldmandowntheroad.html

He take a thunder from the mountain
He take a lightning from the sky
He bring a strong man to his begging knee
He make a young girl's mama cry

These are not typos, both really do sing it like that quite clearly.

Is this meant to emphasize something? Why would they use seemingly broken English?

Solution 1:

Rock and roll music has its roots in the blues, which originated in rural black American communities. Many characteristics of the blues including scales, singing styles, and non-standard grammar, are retained to at least some extent, even in rock music that is far removed from its source in the blues.

The omission of the "s" in the verb is common to many black American dialects, and is nearly universal in the type of blues songs that are clear influences on the lyrics you cite.

Solution 2:

Personally, I think that this page "say" it best: 10 Pop Songs Ruined by Proper Grammar.

"It" just a matter of style and flair.