Scatting is vocalization that isn't lyrics. It is, for the most part, improvisation with wordless vocables, nonsense syllables, whistling, screaming, or even humming without words at all. Scatting gives the singer a chance to improvise his own melody and rhythm, basically creating the vocal equivalent to an instrumental solo. Compare Indecipherable Lyrics and Word Salad Lyrics. Many Lyrical Tics are this. Examples of Scatting include: