Pet Theory III: Formation, Mutation, ApplicationPet Theory III: Formation, Mutation, ApplicationPet Theory III: Formation, Mutation, Application

Pet Theory III: Formation, Mutation, Application Every newly minted musical act goes through three distinct stages. The first if developmental stage called Formation. This is where they start out as naive and sloppy, not exaclty sure what kind of music they are playing and are not really that skilled with their instruments. In the formation stage they are commited to playing one (vaguely defined) kind of music. Everything else is outside of their attention.
The second stage comes when they gain a bit more competence...er...I mean, confidence in their abilities. This also causes another change. They become less dogmatic about genres and ideas from outside of their "pet" genre or style. "Hey, Genre Y ain't as bad as I thought. Lets put some of that in our mix."
But because they aren't as well acquainted with Genre Y as they are with Genre X, they make interesting serindipitous discoveries. This is the Mutation stage.
When they exhaust all the possible "Genre Y's" that can possibly interest them, they finally form a sub-sub-sub-sub-sub-style that uniquely their own.
And now that they have mastered their specific sub-sub-sub-sub-sub-style they proceed to ram it into the ground. This is the Application Stage.
Any act that has enough talent to make an album worth hearing will tend to make their two best (or at least most interesting) albums at the cusp between Formation and Mutation and between Mutation and Application.
The album made at the Formation/Mutation Cusp is what I call their "Punk Protest Album"; this is where they codify the core of their musical ethos and create their boldest, spunkiest and most viscerally appealing record. They might still be primitve, but by now they know where their headed.
(Examples: Revolver, Murmur, War, Master of Puppets.)
The album made at the Mutation/Application Cusp is what I call their "Pop Concept Album"; this is where they master the subtler details of their sound and use up every bit of ear candy in their bag of tricks. This is generally their most well thought out, 'sophisticated' and most well produced album.
(Examples: Seargent Pepper, Automatic for the People, The Joshua Tree, ...and Justice for All.)
After this, they generally end up making an unending stream of increasingly inferior copies of this album until they sink into irrelevance or obscurity.
(Examples: Let it Be, Reveal, Rattle & Hum, Load.)

Side Note: I have noticed that U2 and Metallica are not all that popular on this forum, but you have to admit one thing...both bands were able to (temporarily) suspend their descent into Application Stage Irrelevance & Obscurity.