Answer:

sha

Answer	Crossword Clue
SHA	Doo-wop syllable
SHA	.. Na Na
SHA	... Na Na

SHA	....Na Na
SHA	Cyrillic letter
SHA	Asian wild sheep
SHA	Na Na lead-in
SHA	Doo-wop's .. Na Na
SHA	Oldies act ... Na Na
SHA	"Hush," in Yiddish
SHA	Manfred Mann's "... La La"

SHA	"... -La-La": 1974 hit
SHA	'50s oldies syllable
SHA	'50s song syllable
SHA	Syllable in oldies
SHA	Oldie syllable
SHA	Oldies refrain syllable
SHA	Oldies syllable
SHA	"... Na Na"

SHA	Al Green's "...-La-La"
SHA	Singing group ... Na Na
SHA	The Shirelles' "...-La-La"
SHA	... Na Na (doo-wop group)
SHA	Woodstock performers ... Na Na
SHA	"Grease" band ... Na Na
SHA	Rock's ... Na Na
SHA	TV's ... Na Na

SHA	"Get a Job" song syllable
SHA	"... La La" (Manfred Mann hit)
SHA	"...-La-La (Make Me Happy)" (1974 Al Green hit)
SHA	"...-La-La" (1974 Al Green hit)
SHA	Woodstock band ... Na Na
SHA	"...-La-La" (Al Green hit)
SHA	Doo-wop song syllable
SHA	Start of a doo-wop phrase

SHA	"Get a Job" syllable
SHA	Al Green's "...-La-La (Make Me Happy)"
SHA	..-Na-Na
SHA	..Na Na
SHA	-- Na Na