SPECULUM SPECULI (1972) was written, as its title indicates, for the then newly formed New York ensemble, Speculum Musicae, a second generation descendent of Wuorinen's own ensemble, The Group for Contemporary Music. Speculum Speculi ("Mirror of the Mirror") was first presented on 14 January 1973 in Grand Forks, North Dakota, during a Speculum Musicae tour. Speculum Speculi is a mixed instrument sextet for flute, oboe, bass clarinet, contrabass, piano and percussion (vibraphone, 4 drums, and 3 gongs). For the original Nonesuch recording (currently available on a Music & Arts CD) Wuorinen wrote the following:
"Speculum Speculi is a single, sectionally divided continuity. But it is not "symmetrically" arranged; rather each successive section of the work transforms all of what has gone before. . . The piece begins with a slow monophonic statement of its twelve-tone set in which the time-intervals between successive notes are in direct proportion to the pitch intervals that also separate them. For a second variation, a related set-form is added to a speeded-up transformation of the opening, so that a two-voiced, more rapid music is produced. The third variation transforms both the first and the second, adjoining further material as well: every new section transforms all that has gone before it. Thus the work (albeit in a non-linear way) grows ever denser, and ever faster, as more and more material is necessarily compressed to fit it into a reasonable time frame. But each new transformation, since it always returns for its matter to the very beginning of the piece, preserves a distinct vestige of the single-line opening, whose pitch and rhythmic nature though recurring at different speeds -- remain clearly recognizable."
Wuorinen goes on to write "The foregoing, however, is meant only to provide an initial entry into the work, for I do not propose that it be heard only as a recurring set of transformations. . .the listener, in his response to the music, must ultimately assume active responsibility for what it means to him. Once a work has left its maker, it follows its own life."
"made so forceful an impression that it could hardly be ignored even by those who do not care for contemporary music.... This work for flute, oboe, bass clarinet, piano, double-bass and percussion is full of energy and has an urgency about it that simply cannot be ignored ... its jots and jolts of woodwind colors and drum beats, melodic fragments, contrasts of register and many other elements come together in a vivid musical fabric that insists, quite successfully, on the integrity of its form and the importance of its existence." Allen Hughes, New York Times