Mary Ellen Matthews has photographed every host and musical guest for the show, broke building codes with Sarah Silverman and foisted hair spray on Donald Trump. She just wrote a book about it.

Imagine with me, a single page with 40 lines of this code “A-T, G-C or T-A, C-G” written across and down the page, and where this code is repeated line after line, but in a different sequences. Now ...