I shall appraise the lexical model of Modern English morphology and phonology proposed by Halle and Mohanan (1985), highlighting the abstract and unconstrained nature of this version of LP and arguing for a restriction of the model to two lexical levels. The relationship of the SCC to the Elsewhere Condition, and to Kiparsky's Alternation Condition, will also be discussed. Further invocation of the SCC and other constraints will lead to a reanalysis of certain central rules of the English vowel phonology, in particular the Vowel Shift Rule, and a general appraisal of the appropriateness of the resulting framework for Received Pronunciation (RP) and various American accents. I introduce a further reference accent, Scottish Standard English (SSE), and give a synchronic and diachronic outline of this and non-standard Scots dialects. I shall concentrate here on the synchronic status of the Scottish Vowel Length Rule, assessing whether it applies lexically or postlexically, and also consider its history, thereby establishing a possible `life-cycle' for sound changes and phonological rules. I focus on dialect variation in a Lexical Phonology, with particular emphasis on the impact of radical underspecification on the analysis of dialect differences. Finally, I return to the tension between synchrony and diachrony in phonological theory, considering English /r/ and its present-day and historical interactions with preceding vowels; strengthening the hypotheses put forward earlier on the lexicalization of phonological rules; and indicating that the modelling of rules and changes can perhaps best be dealt with by integrating Articulatory Phonology with Lexical Phonology.