This study of the genesis of Claude Debussy’s mélodies on poems by Paul Verlaine, which present different versions and several modifications, reveals the importance of the place granted to the adequacy between music and textual enunciation. Beyond the relationship connecting verbal semantics and direct musical illustration, Debussy seems to be really aware of poetical diction from the text’s musicality and metrics, as enhanced by Verlaine. My research, supported by a philological study of the sources – both manuscripts and editions –, concentrates on textual diction. For this purpose, I have used testimonies and theoretical writings from the end of the nineteenth century, as well as the very first recordings of poetry declamation and musical performances. These documents have allowed me to shed light on the importance of prosody, of accentuation, of the interpretative reading of the text in its musical setting. This contribution, focalized on rhythm – a notion at the intersection of poetic text and music – tends to re-insert the reality of the poem’s own diction in the performance of Debussy’s mélodies.