The Beatles and Vocal Expression examines popular song through the topic of paralanguage – a sub-category of nonverbal communication that addresses characteristics of speech that modify meaning and convey emotion. It responds to the general consensus regarding the limitations of Western art music notation to analyse popular song, assesses paralinguistic voice qualities giving rise to expressive tropes within and across songs, and lastly addresses gaps in existing Beatles scholarship.

Taking The Beatles' UK studio albums (1963–1970), paralinguistic voice qualities are examined in relation to concepts, characteristics, metaphors, and functions of paralanguage in vocal performance. Tropes, such as rising and falling intonation on words of woe, have historical connections to performative and conversational techniques. This interdisciplinary analysis is achieved through musicology, sound studies, applied linguistics, and cultural history. The new methodology locates paralinguistic voice qualities in recordings, identifies features, shows functions, and draws aural threads within and across popular songs.