From contemporaneous reviews and subsequent music history writings
“For the International Society for Contemporary Music Salzburg was a kind of convent-school from which it has now emerged into the light of public life, for the audience here comprised a much larger proportion of lay folk, and a good sprinkling of the socially distinguished. The Festival is no longer a family affair, but, like other festivals, a function. It is even becoming fashionable. Let us not be too resentful of this, for it materially helps the aims of the Society.
…
“[T]here was still a satisfactory proportion of music such as one wants to hear at least once, and a sprinkling of works likely to be added to the repertoire. It is not merely a charitable view, but the truth, that the Festival may be described on the whole as a success, though it had its dark moments.”
Edwin Evans, “Venice Festival,” The Musical Times, Vol. 66, No. 992 (Oct. 1, 1925), p. 920.
“An event which enables you to be hearing the music of a composer at one moment, and at the next to be confronting his personality, seems in theory to be an ideal arrangement for the obtaining of clear and reasonable judgment. In point of fact the facility increases difficulty; personality works in a strangely contradictory way, and often enough the thought came forcibly home: ‘Good were it for that man that he had never been met.’ Even a musical critic–be he never so austere–cannot be expected to be untouched by personal attributes, and unfortunately the majority, of these younger European composers ignore the claims of ordinary polite human relationships.”
— Basil Maine, “The Prague Festival,” Music & Letters, Vol. 6, No. 4 (Oct., 1925), p. 368.
‘It was an exceedingly interesting and delightful week, and yet I am included to believe that the Society has been, perhaps, a little rash to attempt so soon the arrangement of annual festivals for orchestral music.
“It seems to me now definitely beyond dispute that music which is authentically modern is at its best in compositions of the smaller, more intimate type–in chamber or chamber orchestral works. … Perhaps the day has passed for the great musical scheme, the large orchestra, even the symphony itself.”
Paul Stefan, “Echoes from Prague,” Modern Music, Vol. III #1 (Nov-Dec 1925), p. 31.
“One left Prague with the impression that modern music is still sticking very closely to its leading strings; the music is rare which can, or dare, or perhaps even wishes, to run outside the railings; and it seems that the critics wish it to do so even less. No one can complain that the modern composer does not take enough trouble; he takes far too much, and takes it in the wrong place. One was disappointed at the amount of notes expended upon such a comparatively thoughtless and empty achievement.
…
“[N]ot only does this music need performers of the highest skill–which it rarely gets–but also listeners with highly trained ears–and even the most highly trained would, I fancy, find it difficult to differentiate an unknown piece by one of Schönberg’s pupils from an unknown piece by another. I mention this quality of modern music, not because I imagine it is new, or newly discovered, or because I think, as some do, that after all these queer noises, etc., how nice to go back to Mozart: and all that kind of argument. I mention it because the tendency to write music of a highly complicated texture and nothing else is really running riot in Europe at the moment, and the demand for it increases at a rate which is stifling other endeavor….”
— Hubert J. Foss, “The Prague Festival–Afterthoughts,”
The Sackbut (Volume 5, London July 1925), pp. 347-350. (Accessible online via ProQuest)
“[E]ach time when I hear the chosen works played at the festivals, I ask myself how it is possible that music read in December in Winterthur and executed a few months later in Austria, Czecho-Slovakia or Italy produces such different impressions. Many works, which, when they presented themselves, trembling and timid, before their judges, seemed good or at least passable, are revealed as frankly poor at the performance.
“And this impression is strengthened at each festival organized by the International Society for Contemporary Music…. [It] touches a problem which is essential, even vital, for the future of the Society. There is no need today to point out the benefits of this institution, even if, beneath the beautiful aspect of disinterestedness and international fraternity it conceals the play of intrigues, ambitions and interests. These are after all inevitable. It is nevertheless evident that the choice of works grows steadily more difficult.”
— Alfredo Casella, “The festival at Venice,” Modern Music, Vol. III #1 (Nov-Dec 1925), p. 17.
“Stravinsky’s moment of high anxiety arrived when he performed his Piano Sonata at the 1925 ISCM festival in Venice. Janáček was there; so, too, were Diaghilev, Honegger, the Princesse de Polignac, Cole Porter, Arturo Toscanini, and Schoenberg, with his red gaze. Many questioned Stravinsky’s new neoclassical style; the rumor went around that he was no longer ‘serious,’ that he had become a pasticheur. Schoenberg reportedly walked out.”
— Alex Ross, The Rest is Noise (New York: Farrar, Straus & Giroux / Picador, 2007), pp. 124-125.
“The virtues or inadequacies of the other works in the programmes arise from the fact that their composers either know or do not know (Igor Stravinsky, sonata) that the rules of composition are not exclusive, that they follow the rules of human thought as a whole.”
— Leoš Janáček
reprinted in Janácek and His World, edited by Michael Beckerman (Princeton University Press, 2003), p. 36
(see footnote 70 for source).