The Music of Language

Article: Finding the music of speech: Musical knowledge influences pitch processing in speech. "Even if music- and language-specific processes are observed among adults, this does not mean that such processes are innately domain-specific. Specialization could result from developmental processes and interaction with language and music throughout childhood. Statistical learning mechanisms allow infants to learn the distributional and transitional probabilities in syllables, tones, and even visual shapes. Infant listeners might broadly apply such mechanisms to interpret both spoken and sung input until they have acquired music- or language-specific knowledge or have learned to track specific acoustic cues that are critical within each domain." 

The study of the connection between music and language usually focuses on pitch, but it's the rhythms in words and phrases which also makes them musical. A syllable will either fall naturally on a downbeat or an upbeat. In the phrase, "Little did we know", "little" falls on a downbeat when spoken, but can be shifted for musical effect. You can do this in music but not in everyday language, otherwise it would be incoherent. Music can exist on a loose continuum of coherence and incoherence. Very often pop music will be sung in such a way that you can't make out the words, but it doesn't matter because the music carries you along the surface of the words.