Simply put all vocal work implies releasing the voice, deprogramming all impediments (usually muscular) that stand in the way of a free bright resonant sound. This means the release of what I call the interconnecting highway: the jaw, the tongue, the lips , and the palatal muscles .- all involved in forming vowels and consonants. This is why incorporatng consonants as well as vowels in all their varied combinations in vocal calisthenics is crucial. Each song is a unique vocal landscape. I tell my clients every pitch has a different pull on the body and when they are combined with difficult consonants and vowels as words, we need to do a bit of work to free them up.