Virgil Thomson: Sonata da Chiesa (1926) for Eb clarinet, trumpet in D, viola, horn, trombone.
This is one of the strangest pieces written in a decade delightfully full of strange pieces. Thomson himself considered this to be his "master-piece," in the historical sense of a work written by a journeyman to demonstrate technical command of a craft, and in this case, the dissonant style of the era. (It's composition coincided with the composer's final studies with Nadia Boulanger, and the Sonata da Chiesa must be counted with Copland's Organ Symphony, as among the strongest works to come out of that famous boulangerie).
The strange mastery at work here is most apparent in the instrumentation. The ensemble inverts the usual balance of more strings to fewer winds, and more woodwind than brass in favor of more brass, a single high clarinet and a single string instrument, and that one, the viola, which is least heard soloistically. There is a deliberate choice of instruments with uneasily-matched tonal preferences, with the eb clarinet and the d trumpet more or less dividing sharp and flat keys between one another. Thomson uses ensemble scoring patterns in which none of the instruments is used strictly or consistantly as a high, middle, or low voice, thus the little eb clarinet in chalumeau register can function as the bass and the trombone as a superior alto voice.
Strangest of all is the question of genre. Thomson identifies the piece, by its title, with an Italian baroque form, not the secular sonata, but a multi-movement form intended for use in the Catholic church. But this Sonata, with three movements taking the forms of a Chorale, a Tango, and a technically extravagant Fugue (in which material from the chorale returns with a menace), while ornately baroque on its own terms, is American, more specifically African-American, and churched in an African-American protestant tradition, narrating — if we can trust John Cage on this point — a remembered visit to a Kansas City church service, complete with sermon and congregational response, centered about the Tango's direct confrontation with the diabolical, and with the polytonal fugue suggestion some form of redemption after temptation. It is easy, too easy, at this historical distance, to be uncomfortable with Thomson's racial views, which were liberal but still of their time, and to take this work as a somewhat illicit form of appropriation, but I increasingly hear this piece as an honest act of appreciation and, in his mixture of modernity and elements exotic to both Thomson's white Kansan and European musical roots, something much more than a journeyman's diploma piece.