Final answer:
Jazz vocal improvisation sometimes uses nonsense syllables to make new melodies. This technique is called scat singing.
Step-by-step explanation:
Jazz vocal improvisation sometimes uses nonsense syllables to make new melodies. This technique is called scat singing. Scat singing involves improvising vocal sounds and rhythms instead of using actual words. It became popular in the 1920s and 1930s with jazz musicians like Louis Armstrong and Ella Fitzgerald.
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