We too would love to hear any of Tansman's, and of Yun's.

But since Janacek's (two, third rate, takeable or leavable) and Goehr's the Manchester man and first-rate composer who Professed at Cambridge and at one time taught Roger Smalley (four is it not, gripping, serial and not at all like Janacek! - much more like Dallawhatever) have already somehow had a look in, Members may forgive us for bringing up something fundamental, namely the Four Quartets of Arnold Schoenberg.

The first movement of his Second String Quartet (1908) is one of the most thrilling pieces of music it has ever been our good fortune to encounter - even more thrilling than the Sextet which is saying something. It remains a high point of Western musical culture. The remaining three movements fall rather flatter, as how could they not after that, and the singing was in the end an unfortunate mistake. But the composer evidently invested a great deal of time and effort into the work, which was not at all the case with Erwartung which he become much idler dashed off just twelve short months later. (What trypanosomiasis got into him in the mean-time?)

His Third (1927) and Fourth (1936) String Quartets though are among the best of his later works; they are are they not the acceptable face of dodecaphonism.

While I'm in the mood for seconding things I'll give a 'hear hear' to IGI's recommendation of Stephen Johnson's programme on the Schoenberg Second Quartet. In particular I found myself cheering to the rafters SJ's remarks towards the end of his talk where he was having a little dig at those who argue for the 'historical inevitability' of complete atonality as the necessary next step post-Tristan etc. He was arguing instead, very persuasively I thought, that in the Second Quartet Schoenberg was sketching out, or hinting at, a whole range of possibilities of what could 'come next', and closing none of them off. All was possible. The thoroughgoing atonality of many of Schoenberg's subsequent works was an individual artistic choice from among many other possibilities, not something that 'historical progress' demanded or made inevitable.

[When I say 'argued very persuasively', I suppose I probably really mean that it was pleasing to have my own prejudices on that subject massaged and coddled by someone as knowledgeable and expert as Stephen Johnson. But even so.] 

Not having listened to the programme (although it seems I should), my objection would be that Schoenberg never actually got to a point which could be described as "complete atonality" (nor, I think, would he have claimed to have done). I do think that the gradual loosening of the temporal necessity of tonal relations, announced (though not initiated) in Tristan, did inevitably lead to one of the possibilities being to abandon that sense of necessity altogether (after all, no other musical culture on the planet had been through the stage of feeling it in the first place), after which one of the possibilities would be to substitute some other "necessity" such as Schoenberg's twelve-tone method. Other composers did conceive of similar methods at about the same time, indeed, though it's unlikely that they would have gained the currency that they did without the advocacy of a personality as forceful as his. However, there were many paths away from tonality which were basically independent of Schoenberg's: Ives, Varèse, Scriabin, Scelsi, Xenakis...

Quite right, and I'm particularly glad you said "tonally centred...thinking" rather than "tonal thinking" -- in this regard I recall the composer Max Reger's line "any chord can follow any other chord." Thereafter it was just a matter of time before people realized that (1) "any note can follow any other note, or accompany any other note" and (2) "if I remain tonally oriented, there is no reason other than habit why my work should begin and end in one and the same tonality." The limits to these two principles were only the composer's volition and not some ponderously posited universal.