Albums have 4 stats.
2 of the stats are ranked 3-18 (you know how that shit works).
2 of the stats are derived from the other 2.
Music (Mus): This is how much I like the sound. Ranked 3-18.
Art (Art): This is how much I liked the album art. Ranked 3-18.
Disharmony: This is how closely matched the Mus and Art are. Like descending AC, you want a low number. It is the absolute difference between Mus and Art, rounded down.
Level (Lvl): This is the album's overall power. Ranked 0-9 where 0 should stay home and 9 is name level, lording over a keep. It is derived from a secret forumla based on Mus and Art (add them, average, round down).
In my head, albums ranked in this way are PCs about to embark on a deadly adventure such as G1: Steading of the Hill Giant Chieftain. But it strikes me that an adventure for levels 6-8 would work better. I just need to think of a good one.
Greyhawk "Keepers of the Flame"
I feel like I accomplished something this morning.
EDIT: I changed "Harmony" to "Disharmony" since that is what I was actually going for. The idea is that if the art and music score the same, then they are in perfect alignment. The higher the Disharmony, the less the art and music are in synch. This is important.