Nope. In fact, it *IS* a mix of gangsta rap and bluegrass, and when you think about it, this really makes rock come full circle to its roots. This is a very interesting sound, a little like old time blues, sea shanties, and mountain music with some deep rap. How does that work? A lot better than you expect, and here's the clever part that opened my eyes to this: rap is a form of blues. Think about it. Think about those old time records from the 1920s where some "negro" sings about his woman leaving him, how "the blues" got him down. The whole genre is about things gone all wrong, and accepting your miserable life as the status quo. And so does most rap. Some of the detailed subject matter is more modern, like riding in cars and shooting people, but most rap doesn't speak about this being a good thing, but a stark acceptance of the horror of day to day reality. Which goes back to blues.
And these artists did a really good job with joining the two at this common root. The first track, "Goin' Down" is an excellent way to see this.
"But I hate gansta rap AND bluegrass!" You say. "I will hate this twice as much!"
You'd think that. And you'd be right. But if you want to hear an interesting mix that may make a lot of musicologists nod in an all-knowing way, this is bringing the rock and roll full circle.