Introducing RapMetrics™: The Birth of Statistical Analysis of Rap Lyrics

I’m leading the league in at least six statistical categories right now
Best flow, most consistent, realest stories
Most charisma, I set the most trends
And my interviews are hotter

— Jay-Z, from “Breathe Easy”

Imagine this: you are sitting in your Goldman Sachs interview, and the hiring partner busts a Jay-Z, claiming dominance across different statistical categories (“Most IPOs, highest leverage” etc.)

What would you say?

A: You would say “QUANTIFY THAT SHIT!”

Well, that’s exactly what Rap Genius has to say to Jay-Z: while ‘best interview’ isn’t an easily measurable metric (and to be honest, he’s barely a top-10 interview), we actually can, using state-of-the-art linguistic analysis software, quantify Jay’s performance in some other rap categories like speed, vocab variety, word length, etc. the same way we come up with statistics for sports (or finance).

Let’s take a look at our most powerful stat: Rhyme Density™. Rhyme Density™ equals:

(Total number of syllables that are a part of a rhyme) ÷ (Total syllables)

So in a song with a rhyme density of .30 (Jay-Z’s career average btw), 30% of the syllables are part of rhymes, and 70% are not.

Rhyme Density™ basically tells you how efficient a rapper is: like a Native American who uses all parts of the animal to sustain his life, an efficient rapper uses all parts of a line in his rhymes.

To give Rhyme Density™ some teeth, compare these two verses:

1 — From Eminem’s “Without Me” (rhyme density = .49)

2 — From Notorious B.I.G.’s “Juicy” (rhyme density = .23)

Now, this isn’t to say that “Without Me” is a better song than “Juicy”. Different song styles will yield different numbers. BUT — we do contend that over the course of a career, the rappers with the highest rhyme densities are basically the best technical rappers.

So Based on Rhyme Density™, which rappers test out the best?

  1. MF Doom .44
  2. Cam'ron .41
  3. Big Pun .40
  4. Eminem .38
  5. Fabolous .36

MF Doom surprised us a little. First the big New Yorker profile and now this…it’s too much! Cam'ron is much more culturally relevant and interesting (plus he doesn’t need to wear a mask, he’s naturally silly), so we at RapMetrics™ consider him the G.O.A.T. MC overall.

Cam receiving the call from RapMetrics™ with the news that he’s the G.O.A.T.

Here are some other RapMetrics™ insights (visit the RapMetrics™ blog for more):

  1. Jay-Z significantly upped his Rhyme Density for “Renegade” (.46) relative to the rest of his career (.30), probably in order to match Eminem’s dense style.
  2. Joe Budden generally has low rhyme density (~.25) and very long lines. The reason he’s considered such a complex artist (post-“Pump It Up”) has more to do with complex emotions than complex rhymes.
  3. Kanye’s best song rhyme-wise is “Jesus Walks” (which he admits was “co-written”by Rhymefest).
  4. Rappers who use big words tend to sell fewer albums.

Of course, some RapMetrics™ results are just too counter-intuitive to accept. Illmatic and Blueprint don’t really stand out as albums, RapMETRICally™ speaking — even though in real life they are two of the hardest albums of all time. Notorious B.I.G. is quantitatively average, while ACTUALLY he was one of the best rappers who ever lived. What RapMetrics™ does is provide a basis for who is good, technically speaking. Quality of music doesn’t necessarily mean great technical ability, so take it all with a grain of salt.

OUR VISION: One day, nerds are going to be arguing online about rap using numbers instead of their totally worthless subjective opinion! This is the goal of RapMetrics™..

RAP NERDS: If you have any hypotheses you’d like us to test, let us know in comments…

It’s all mathematics!

Note: This analysis is done by Liban Ali Yusuf of RapMetrics™ which is based on a peer-reviewed paper found here