Improvises nonsense syllables

• Vamooses
• Sings jazz riffs like Ella Fitzgerald
• Sings in an a capella group, perhaps
• Sings like Cab Calloway
• Does some impromptu singing
• Sings jazzily
• Hightails it
• Leaves quickly

Wiktionary Word definitions in Wiktionary
vb. (en-third-person singular of: scat )