The interplay between categorical and continuous aspects of the speech signal remains central and yet controversial in the fields of phonetics and phonology. The division between phonological abstractions and phonetic variations has been particularly relevant to the unraveling of diverse communicative functions of pitch in the domain of prosody. Pitch influences vocal communication in two major but fundamentally different ways, and lexical and intonational tones exquisitely capture these functions. Lexical tone contrasts convey lexical meanings as well as derivational meanings at the word level and are grammatically encoded as discrete structures. Intonational tones, on the other hand, signal post-lexical meanings at the phrasal level and typically allow gradient pragmatic variations. Since categorical and gradient uses of pitch are ubiquitous and closely intertwined in their physiological and psychological processes, further research is warranted for a more detailed understanding of their structural and functional characterisations. This Research Topic addresses this matter from a wide range of perspectives, including first and second language acquisition, speech production and perception, structural and functional diversity, and working with distinct languages and experimental measures. In the following, we provide a short overview of the contributions submitted to this topic