Lexical tone refers to the pitch of speech as a vehicle for semantic meaning. The importance of pitch to conveying musical ideas is well-known, but the linguistic importance of pitch is less obvious. Tonal languages such as Thai and Cantonese, wherein the lexical meaning of a sound depends heavily on its pitch relative to other sounds, are seen as evolutionary artifacts of musilanguage. Non-tonal, or "intonation" languages, which do not depend heavily on pitch for lexical meaning, are seen as evolutionary late-comers that have discarded their dependence on tone. Intermediate states, known as pitch accent languages, which exhibit some lexical dependence on tone, but also depend heavily on intonation, are exemplified by Japanese, Swedish, and Serbo-Croatian.