We now know what it might sound like if Walt Whitman and Big Sean wrote lyrics together: Mental Floss fed famous lines from classic literature into the rap lyric creation site RapPad and paired them with lines from successful rap songs. RapPad lets you make your own raps using rhyme lookups, syllable counters, and a collection of beats. But the Generate Line feature lets you experiment by typing in your own text and the website will fill in the next line using its lyrics library. …