Musictionary
“Scat: Scat singing is utilized by Jazz singers who vocalize either wordlessly or with nonsense words and syllables. As with other Jazz improvisations, scat improvisations are made with the melody and rhythm as opposed to using sounds to exactly reproduce melodic lines. Scat singing gives singers the ability to sing improvised melodies and rhythms to create the equivalent of an instrumental solo using their voice.
Did you know? Louis Armstrong's 1926 recording of 'Heebie Jeebies' is often cited as the first song to employ scatting.
Dave Matthews, of Dave Matthews Band, is also a noted enthusiast of vocal scatting, often employing it into songs during live performances. During periods of improvisation, Matthews will begin to insert broken phrases and words as well as more traditional forms of scat in combination.
Ella Fitzgerald is generally considered to be one of the greatest scat singers in Jazz history.”