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I'm thinking Fall Out Boy's "Rat A Tat" it's not exactly like you're describing but it's fairly similar
There is no justice, Just Us.
It is not that.
You could try this site http://www.whosampled.com/Missy-Elliott/Work-It/
That site was the first place I looked. It's not a direct cut-and-paste sample - the rapper/artist in the cover song does that part with his own voice. So I guess that website won't have it...
Actually, Whosampled does also list samples that are interpolations, or, a part of a song (melody, lyrics, drums, bassline, etc.) that has been recreated from scratch.
Saving the world, one fret button at a time.
A song that samples part of Missy Elliott's "Work It". The part in the question is when she says "This the kind of beat that goes ra-ta-ta, ra-ta-ta-ta, ta-ta-ta-ta-ta-ta."
The song I am thinking of slows down the beat a little bit, and that "ra-ta-ta-ta" sample is part of the chorus. It plays in the beginning, and I think the rapper's line opens with "Ay yo". I want to say it's Lil Wayne or Will I Am or someone else with a sort of harsh voice. I have tried to find this song but I can't!