Sam Does it allow you to get overhead shots?
Yes but it depends on where you put it. Here's a screengrab from my first practice recording, in this photo the stand is on the shelf to the left, where you can see it in the photos in my first post, so it's not perfectly overhead, but it gives a good view of both hands. And I literally popped the phone into the holder and took the video, without experimenting with different angles. Anyway here's the photo:

(edited to upload a smaller photo)
The stand isn't tall enough to be placed on the floor, but if you could get one with this design, with the heavy base, then I would imagine you could place it on the floor behind the bench.
I might also try putting it on the folded back flylid, but that would mean you definitely can't record with the lid up. Still, that might work well. I think the base has felt on the bottom, so it shouldn't scratch the flylid, but I might put out something thin like a hankerchief or pillowcase and then put it on that. I'll report back if I try.
Oh, I meant to say - it will not fit on the side of the music desk (on a grand), partly because the base is too large, but moreso because it's just too heavy and I wouldn't want that weight on my music desk.