In addition to being of personal interest (I think it's much more difficult and impressive to create rhymes with 3+ syllables due to the natural constraint of a smaller basket of words), it would also, presumably, avoid the issue that the author highlights:

> I used a research methodology called token analysis to determine each artist’s vocabulary. Each word is counted once, so pimps, pimp, pimping, and pimpin are four unique words. To avoid issues with apostrophes (e.g., pimpin’ vs. pimpin), they’re removed from the dataset. It still isn’t perfect. Hip hop is full of slang that is hard to transcribe (e.g., shorty vs. shawty), compound words (e.g., king shit)