Heard? Yes.
Heard of? That would suggest that "sha la la" is a _thing_.
Perhaps you mean the song "Sha la la", recorded by
the Shirelles, later by Manfred Mann? The lyrics
contain some remarkably extended variants of the
mystic syllables:
(Sha la, la, la, la, la, la)
(Sha la, la, la, la, la, la, la)
(Sha la, la, la, la, la, la, la, la, la)
http://www.lyricsfreak.com/m/manfred+manns+earth+band/sha+la+la_21034811.html
Or perhaps you had something else in mind?