The aim of this paper is to show that a sequence of typologically not unusual sound changes has led to three conspicuous properties of the dialects in a large connected area of Low and Central Franconian. First, these dialects have a binary contrast between acute and circumflex tones. Second, the majority of these dialects (“group A”) show length reversal, in the sense that originally short non-high vowels have become longer than the corresponding originally long vowels. Third, the remaining dialects (“group B”) show tone reversal, in the sense that where group A retains the original acutes, group B has circumflexes, and the reverse (at least in declarative intonation). This paper proposes a history consisting of a series of synchronic states connected by speakers’ gradual phonetic shifts and listeners’ discrete phonological reinterpretations. Each of the proposed elements is shown to have parallels elsewhere: the retraction of stress to the first mora, the lengthening of vowels in open syllables with retention of the linkage between syllables and tones, the inaudibility of tone on voiceless consonants, the drop of final schwa, the pronunciation of final voiced obstruents, the audibility of tone on voiced consonants, the devoicing of final obstruents, degemination, schwa insertion, and the effects of a markedness constraint that correlates tones and duration.