Sound stage height??

I notice that with most recordings I get a full height sound stage, as though I'm sitting right in front of the band. With other music it's more like I'm sitting above the band...........vocals seem to come from lower than my listening height............It's an odd phenomenon. I can only attribute it to how the music was recorded. It can even vary with different songs on the same disc......................My sound stage is typically wall to wall and realistically deep behind the speakers.............but sometimes it's almost like the vocalist is sitting on the floor in front of the band...........Anybody else experience this??................Marantz SA14s1 CDP...........Bryston amps...........Vandersteen 3A speakers...........room is well treated acoustically.