xiii, 188 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / Beethoven's last five string quartets have engaged the imagination and curiosity of performers, listeners, and critics at a level that has rarely been touched in the world of chamber music, or beyond. Throughout the late quartets' history, musicians have scrutinized the works in search of a logic that might demystify their stylistic and structural peculiarities. This present study continues this pursuit as it examines analytically (through Schenkerian techniques) the harmonic, contrapuntal, and motivic procedures in Beethoven's last complete composition, the String Quartet in F major, op. 135. Most of the published analytical commentaries on the F major quartet approach the work more or less exclusively from a motivic standpoint. Arnold Schoenberg (1941), Rudolf Reti (1951), Deryck Cooke (1963), and Christopher Reynolds (1988) have all praised op. 135 for its highly unified motivic structure; what their studies show--at least in a general sense--is that there is undoubtedly a motivic strategy that ties much of op. 135 together. But what are we to do when the details of one motivic reading opposes another? Or what if a particular reading contradicts the way we understand a passage aurally (which happens often when the proposed reading is incongruous with the music's harmonic-contrapuntal structure)? What criteria should we use to evaluate a motivic analysis? Clearly, we need a set of principles and standards that will help answer these questions and advance us beyond mere intuition. The position taken in this study echoes John Rothgeb's argument that "proposed thematic relationships must bear scrutiny in the light of the Schenkerian theory of structural strata," and that incompatible readings should be "dismissed as spurious" (1983, 42). In the pages that follow, Schenkerian approach is adopted to help assess existing motivic readings of op. 135 within the requisite contexts of harmony and voice leading. The method is also used to help generate a rational, hearable analysis that reveals motivic relationships that reside at deeper, hidden levels of structure. / Adviser: Jack Boss