There are several ways to adapt a poem to a new medium and create a song based on it (reference, continuation, parody or reflection). One of the most common methods is setting poetic texts to music with minimal interventions, such as transposing, repeating, or even omitting verses. It is commonly thought that this type of musical adaptation disseminates the poem and gives it a new life in another medium, but studies of the textual mechanisms which come into play and their rationale are scarce. This work presents an analysis of almost a thousand musical adaptations of poems that elicits the most frequent types of modifications, teasing out the criteria for the addition, deletion, or repetition of verses or sequences. Our corpus was provided by the PoeMAS project, which collects, in a public available database, a wide variety of Spanish lyrics (from 1975 onwards) based on poems. Each entry provides valuable metadata (publication date, performer or author, genre, etc.), and the texts for poem and song. An automatic collation of each poem and its musicalisations was performed. The textual differences are then categorised by implementing a taxonomy that draws from the theories of intersemiotic translation (Jakobson, 1959; Romano, 1994, 1999) and intermediality (Rajewsky, 2005; Wolf, 1999). This systematic classification of changes between poem text and song allows us to reach conclusions about the types of adaptations and to work on the criteria underlying these modifications in lyrics, explaining why some verses or sequences are repeated, omitted, added, or changed. REFERENCES: Jakobson, R. (1959). On linguistic aspects of translation. En R. A. Brower (Ed.), On translation (Vol. 3, pp. 30-39). Cambridge, Massachusetts: Harvard University Press. PoeMAS UNED - Poesía para más gente. Relación entre poesía y música. (n.d.). Retrieved 29 April 2022, from PoeMAS website: https://poemas.uned.es/ Rajewsky, I. O. (2005). Intermediality, Intertextuality, and Remediation: A Literary Perspective on Intermediality. Intermédialités, (6), 43-64. https://doi.org/10.7202/1005505ar Romano, M. (1994). La canción de «autor» en el cruce de escritura y oralidad. En L. Scarano, M. Romano, y M. Ferrari, La voz diseminada: Hacia una teoría del sujeto en la poesía española. Buenos Aires: Biblos. Romano, M. (1999). Un diálogo selecto: Góngora y Paco Ibáñez. Letras, (52), 105-120. Wolf, W. (1999). The Musicalization of Fiction: A Study in the Theory and History of Intermediality. Amsterdam: Rodopi.