Flashbackked

Lately I've been thinking a lot about the cinematic flashback cliche where the screen goes wavy and a harp runs through its tonal scale. I seem to remember this being a running gag throughout Johnny Dangerously:

Michael Keaton: (starts reminiscing, screen goes wavy)

Boy: Wait, what the hell is going on?

Michael Keaton: Don't worry, it always does this when I talk about the past.

Or something like that. I saw this 30 years ago.

But the wavy screen/harp scale trope wasn't always a cliche--some enterprising editor or director created it, and the effect must have worked well to have had it repeated so often.

I'm trying to locate the first instance of the wavy screen/harp flashback effect. I haven't been able to find anything online yet.

If anybody knows anything, please let me know!