Hm, I would rather recommend it the other way around.
If the background is brighter than the actual object it tends to fade the object, since as brighter a part is as more it catches the attention, so I myself would recommend to tone the background darker.
But it is up to you, you can experiment with the glow, maybe it looks even better if the ocarina is darker, but not as dark as the glow fades the ocarina.