You've made me cry now, you nasty man.

Do farmers have henchmen?

(See this morning's papers if you don't know what I'm talking about.)

Good question. One possible example, I think, would be the work of Hindemith. After a somewhat Straussian beginning, his music of the 1920s and early 1930s generally follows no rules other than his own exuberance and penchant for neoclassical counterpoint. Subsequently he codified what he thought he'd been doing, in the form of his book Unterweisung im Tonsatz, which is based around a theory of tonal harmony ranking intervals from most consonant to most dissonant, and henceforth his music seems to be primarily concerned with demonstrating these theoretical principles rather than with following his musical intuition.

Having said that, I don't think it's at all necessary for there to be a conflict between "system" and "judgement", and it's no more or less likely for a serial composer to be the unthinking slave of that particular system than it would have been for a composer of Mozart's day to have been the slave of the stylistic practice of that time. The real issue here is the imagination and communicative motivation of the composer.

Certainly that is true. It applies too for instance to the music of Frank Bridge (neglected for seventy years) Joseph Holbrooke (still neglected) to Bowen and countless others whose finest works moulder in the library stacks in all European countries.

Part of the reason is that the bulk of listeners is incapable of appreciating the music of really fine composers. It is too good for them; over their heads! Therefore a really fine composer is deluded if he relies upon dissemination by way of the concert system. Fortunately alternative ways of bringing one's work to the public are at last coming into existence. The Albert Hall and Radio 3 with their interminable repetitions of old war-horses will themselves fade into oblivion. Through universal availability the decades to come will bring the final triumph of true taste. Persistent volunteer workers though are required to penetrate the libraries before it is too late.

The real "issue" here "is" neither the imagination nor the communicative motivation of the composer. Oh no it is not those at all! (And in any case they are surely different so the proposition should read "issues" with an "s" "are" should it not? Then it would be they that would not be those.) The real and important considerations are our composer's capacity for intense sedulous work and his sense for Art. To the true composer absolutely nothing apart from Art matters. Art is the only reality he will tell you. More specifically, "imagination" (German "Vor-stellung" say) is the presentation to the mind of some thing or quality external to it. Musical creation is the opposite - the impression upon an external medium of mental movements - the moulding and re-formation of Nature as a mirror of Spirit.

And then there is this:

Paul Hindemith! Let us not tolerate his traducement without reason. Here is what he actually had to say about "rules" in music:

"Let us investigate briefly some of these allegedly 'modern' achievements. The best known and most frequently mentioned is the so-called twelve-tone technique, or composition in pre-established tone series. The idea is to take the twelve tones of our chromatic scale, select one of its some four hundred million permutations, and use it as the basis for the harmonic (and possibly melodic) structure of a piece. This rule of construction is established arbitrarily and without any reference to basic musical facts. It ignores the validity of harmonic and melodic values derived from mathematical, physical, or psychological experience; it does not take into account the differences in intervallic tensions, the physical relationship of tones, the degree of ease in vocal production, and many other facts of either natural permanence or proven usefulness. Its main 'law' is supplemented by other rules of equal arbitrariness, such as: tones must not be repeated; your selected tone series may skip from one stratum of the texture to any other one; you have to use the inversion and other distortions of this series; and so on all of which can be reduced to the general advice: avoid so far as possible anything that has been written before.

"The only segment of our conventional body of theoretical musical knowledge which the dodecaphonists have deigned to admit and which, in fact, alone makes their speculations possible, is the twelve-tone tempered scale. We have already been told of this scale's weakness: because of its basic impurity it can be used only as a supplementary regulative to a tone system containing natural intervals at least, so long as we want to save our music from total instrumental mechanization and have human voices participate in its execution. True, some kind of a restricted technique of composition can be developed on a foundation of compromise scales and arbitrary working rules, but doubtless the general result will always be one similar to the kind of poetry that is created by pouring written words out of a tumbler without calling in grammar and syntax. A higher tonal organization is not attempted and cannot be achieved, especially if one permits the technical working rules to slip off into the aforementioned set of supplementary statutes which are nothing but stylistic whims and, as such, not subject to any controlling power of general validity. Of course, there are those super-refined prophets who proudly claim that they can, by the rules of this stylistic method, write pieces in C major, which seems to be a procedure as direct as leaving one's house in New England through the front door and entering the back door by a little detour via Chicago."

He puts it well does he not? We love that "possibly melodic," and he is so right to despise "arbitrariness." But the "intervallic tensions" are the main point and the great thing.

One debate du jour in American new music is "notes vs. sound;" in other words, whether harmony is important apart from its contribution to a particular quality of sound.  The very die-hardest partisans of "sound," most of whom seem to be under 40 years of age, are (ostensibly) not concerned with harmony qua harmony - so they'd meet this description.  Although extremists of this sort are rare, I do know a couple of composers who flatly refuse to write for the piano because they feel they have nothing to say in a medium defined so strongly by "notes" whose historical killer app, so to speak, is the ability to play in any key.

I'd also mention that Cage's early music ("In a Landscape," "Suite for Toy Piano," etc.) evidences a certain individual taste in harmony, if not an "interest" in it.