something doesn't have to be science to be studied by
science.

true - any and all phenomena are studied by science

Even religion can be a *subject* of science, while
clearly it is not science itself.

only if you are referring to quantifiable and measurable neurological phenomena occurring while people are in altered states resulting from 'religious activity' -- other than that it is purely philosophical (read: subjective) conjecture and debate

Bregman's scene analysis is biased to western culture - I wonder if the results from these same tests could be replicated with a remote tribal population in South America?

we construct the world around us on a moment-to-moment basis and how we build it is determined by our entraining via culture, education, training, emotional state and environmental context over a lifetime and differ widely from person to person -- so stating that musical psychoacoustics can be generalized (and not voodoo) is opinion, not fact...
:)