Abstract
Generalized theories of formal functions have yet to adequately capture the temporal experience of musical form. Recent research into musical performance suggests that sounded interpretation may generate temporal formal functions of its own. This thesis is elaborated through a discussion
of Friedrich Gulda's and Alfred Brendel's contrary readings of Beethoven's Adagio sostenuto, the third movement of the "Hammerklavier" Sonata Op. 106, within a corpus of 27 analyzed recordings of this movement between 1936 and 2021. Both Brendel and Gulda were in contact with post-Schoenbergian
methods of musical analysis in Vienna around 1950. A review of Erwin Ratz's analysis of Op. 106, iii and the recordings' differing temporal designs demonstrate the conflict between an architectural conception of the movement, in which caesuras are strengthened, and a process-like interpretation
that sustains the impression of continuity and flow across the sections by means of superordinate tempo progressions. This tension between interpretations is superimposed onto the specific formal ambiguity of this movement, which oscillates between sonata and variation form. To incorporate
such dimensions of sounded interpretation more consistently into form-analytical methods, a music-theoretical "quantum theory" is required that respects the basic ambivalence of formal function in performed time.