My Two-Bit Opinion #7: Colter's New Critical Tool for Music
Ordinarily I'm not in favor of pigeonholing and categorizations, but in these times of popular artistic breakdown I feel it necessary to separate things out for better ease of understanding and critique. Today's music "artists" come in many ontological shapes and sizes - with several methods for achieving artistic success. Too much artistic criticism stems from a dualistic scale ranging from "bad" to "good." A dualistic, one-dimensional scale is simply an ineffective critical tool, so I suggest a two-dimensional map that at least attempts some measure of objectivity:

What I've done here is set up two axes, one of style versus substance and one of composer versus performer. These distinctions should not be mistaken for dualities - a composer is not any more or less valid than a performer, nor is style to be considered the antithesis of substance. A location close to the middle of the grid indicates a balance of these tendencies. For example, I consider Frank Zappa to have been a uniquely styled, substantive composer and performer. Some brief definitions of my terms:
Substance: What ones says
Style: How one says it
Composer: One who writes music
Performer: One who performs music
Different genres have different emphases on the grid. Blues and rock music for example are heavily oriented toward performance and style. In these genres, what is generally preferred by the audience is a unique style and an affecting performance. Compositionally, rock and blues use the same chord forms and progressions repeatedly. So rock and blues (and their offspring, pop) generally occupy the lower right corner. However, in the map above, notice that B.B. King's "substance" rating is considerably greater than Christina Aguilera's.
An explanation of the example artists:
Frank Sinatra was an exceptional performer who composed very little. He does have a unique style, although he is part of a tradition of "crooners," so he is best described as substantive performer.
Igor Stravinsky was a composer who played an instrument very rarely. Many of the greatest composers today are not performers, and this is particularly the case in classical music where there is a significant gulf between composers and performers. His works were uniquely styled, but it is his musical and emotional substance for which he is most known.
Andrew Lloyd Webber, on the other hand, gets by mostly on style.
Frank Zappa, Dave Matthews and Prince all maintain a relative balance. Each are so unique as to be unparalleled in their creation and performance of substantive music. Although Prince leans further away from the substance side as his lyrical subject matter is often limited to the popular, cliched areas of sex and love.
Christina Aguilera, as with most pop artists on the charts today (whether rock, hip-hop or R&B) is entirely a stylish performer.
B.B. King, although firmly ensconced in blues tradition, performs much more substantive material with deeper emotional impact than Ms. Aguilera.
Notes on Genre
The definition of excellence in a particular genre is often relative to the genre itself. In blues and rock, it's not what you say but how you say it. In classical, the composition on paper is as important as its performance - although the performance is often so precise as to negate any individual expression of the performer. In jazz, the composition is important on paper, but the improvisation of the performer allows for individual expression. Therefore, jazz can be considered a highly balanced genre. It is the synthesis of the classical and rock-blues ethics.
There are so many ways to be great in music. This map really needs a third dimension for relative "excellence," but as that is an inherently subjective judgment, I'll leave it up to you to decide for yourself.
And for heaven's sake, I'm just making this up as I go, so I could be entirely wrongheaded about all this.