Well, exporting a frame as an image, reimporting it back in, and wedging it between clips as a single frame, lot of work relatively speaking. Does it really show up that bad in playback, just one frame? I’d say just leave it. If you’re trying to clean things up, I’d just cut the frame out.
I just did some experimenting on various clips of folks in minor action including lecturers waving their hands around, and yes musical performances, and if you just cut out one frame, I’m finding it won’t be noticed. I’d just cut the bad frame out and leave it at that.
If you do see a jump, it’ll probably be only you (knowing what you did) who notices it. If you add a frame, you’ll get a freeze for that frame. If it’s noticeable, I’d rather the jump than the freeze. But again, I bet if you just cut one frame out you’ll be fine.
P.S. As a musician and composer, love Art’s work!