scat singing vs scat

scat singing and scat both are nouns.

Word	Noun	Adjective	Verb	Adverb
scat singing	Yes	No	No	No
scat	Yes	No	Yes	No

As nouns, scat singing and scat are synonyms defined as:

scat singing and scat: singing jazz; the singer substitutes nonsense syllables for the words of the song and tries to sound like a musical instrument

scat singing (noun)	scat (noun)
singing jazz; the singer substitutes nonsense syllables for the words of the song and tries to sound like a musical instrument	singing jazz; the singer substitutes nonsense syllables for the words of the song and tries to sound like a musical instrument

scat singing (verb)	scat (verb)
	flee; take to one's heels; cut and run