Final answer:
Scat singing is a technique in jazz vocal improvisation where nonsense syllables are used to create melodies.
Step-by-step explanation:
The technique in question is called scat singing. Scat singing is a form of vocal improvisation in jazz music where the singer uses nonsense syllables to create melodies and rhythms. It is a way for jazz vocalists to express themselves creatively and add their own unique touch to a performance.
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