From what I remember, it’s an older painting and it’s of a devil sitting next to (or on) the bed of a man and it looks like he’s having a bad dream. The devil or demon is playing a cello or violin into the man’s ear and it looks like the man is having a terrible dream.
First link locks me out. But in that second link I do see a similar pic, but that’s not the one. The one I saw was very colorful, very realistic, but it was renaissance period.
First of all, the first link will work if you paste it into your browser. Secondly, the picture it displays is indeed colorful. Thirdly, if that’s not the picture you’re looking for, then you’ve seen a work of blatant, shameless plagiarism.
“Tartini dream” as an image search turns up a treatment by another artist as well (James Marshall) from 1868 (not renaissance, actually, but the style looks rather traditional):
Unfortunately, I can’t find anything but that thumbnail. There are many references to the other one, which was by Louis Leopold Boilly. Marshall seems to have been rather obscure, and it’s hard to search for him because there are multiple James Marshalls, including at least two contemporary artists.
I’ve seen a different version than the one linked to as well. The background is dark colors, but it’s pretty realistic. Instead of a side view of the scene, the old man in pointed towards the viewer feet first. He grimaces in his sleep, and his face is more of a “close up.” I have no idea when or where I saw it, sadly.