Accordionist David Lee Garza's leadership through memorable pasadas indicates that the accordion guides the melodic and harmonic direction of each song. Because the accordion is the central focus of the band, whose songs develop through experimentation, I hypothesize that the chord progressions in the songs of conjunto music, specifically that of David Lee Garza y Los Musicales, result from the physical layout of the accordion. I develop two accordion-based Tonnetze—one for the five-row accordion and one for the three-row—and observe progressions of fifths-related harmonies as well as progressions through adjacent Roman numerals (i.e. iii-IV- V, in which there are no common tones shared from chord to chord and therefore involve shifting all three pitches to a new chord). Using six songs by David Lee Garza y Los Musicales between 1995-2002, I analyze this non-notated music with a Tonnetz, lyrics, form, and chord progressions. I also highlight any relevant chordal progression differences between the five- and three-row accordions.