verbs - The grammaticality of "that don't impress me much"

I'd like to know how the sentence "That don't impress me much" sounds to a native English speaker.

The phrase is the title of a song by Shania Twain, and to my eyes it contains a clear error. It is obviously intended, and I want to know what was the effect that the author wanted to obtain.

Other examples that come to mind:

• “She's got a ticket to ride, but she don't care” — The Beatles


• “My love don't cost a thing” — Jennifer Lopez


• “It don't matter” — Akon


• “She don't care about me” — heard in the Lost series


• “It Don't Mean a Thing” — a jazz album title


• “The Sun Don't Lie” — another album title

Answer

The intentional misuse of don't is a form of code switching (or code mixing). The form is extremely characteristic of working-class southeastern Americans ("southerners"), who are also the primary audience for American country music.

What is most interesting about the song is that Shania Twain is Canadian — and that is where the code switching begins. It is a deliberate error made in attempt to establish authenticity and to better connect with her music's intended audience.