Birth of the Cool

I am backing my computer onto DVDs.
In order to maximize space, I sorted my music files by size.
Since i-Tunes organizes music by artists, I was able to see who takes up the most space on my hard drive:

(top twenty in order)
Miles Davis
Bob Dylan
Leonard Cohen
Velevet Underground
Morrissey
Johnny Cash
The Clash
Violent Femmes
Pixies
Frank Sinatra
Devo
The Smiths
Talking Heads
The Beatles
Love
X
Elvis Presley
Nirvana
The Rolling Stones
The Replacements

What is weird is that some bands have higher-quality recordings that take up more disc space, so this is not a reflectiosn of the number of songs nor of the length of the tracks of the songs.