"Now that's what I call a harpy!" Image source: vidcap from "Fashions of 1933" a pre-Code Busby Berkeley movie.
Alternatively: "In her case, the "g" in "g spot" stands for "glissando."
Busby Berkeley got away with one hell of a lot of kinky stuff before the Hays Code rang down an iron curtain on filmmakers. This is definitely part of the "human furniture" kink, which mostly consists of human tables and chairs, but in the case of harps, you get that imagery now and then, and by "now and then" I mean "almost never." This image and the one below are just about it for the theme, that I know of.
A cutie harpy. Image source: this is a VERY old jpg that most likely predates the World Wide Web, yeah, we're talking Newsgroup stuff. Ran it through the usual sources, no luck at all for a point of origin, or even a match of any kind. Probably scanned from some bondage magazine, however, the sloppiness of the ball gag and the bondage makes me think it might even have been a mainstream porn mag sliding a little kink in.