There are a few different approaches you might take to finding interdisciplinary articles that cover both music and literature. One is to search an interdisciplinary database, like Discover or JSTOR, that covers all subject areas. In that case, you'd want your search terms to include "music" or related terms, and the name of an author, specific work of literature, or a type of literature (e.g. Irish literature). Another is to search in a subject specific database, covering either music or literature, on the topic that you might not normally think of searching in that subject database. In the case of a music database, like RILM/Abstracts of Music Literature, your search terms should include a specific literary author or work, or, more broadly, Irish literature. In the case of a literature database you might try the opposite, searching more heavily on musical terms expecting that you'll find articles that talk about the use of music in literature. MLA International Bibliography, however, covers not only literature literary theory but also related fields (dramatic arts, folklore, and linguistics). It's best to search "music" or related terms combined with a specific author, or work, or possibly type of literature (e.g., Irish literature).
Clicking the MHLinks button for an article will help you locate the full text.