You asked for "A link to a site explaining, in sound, the different scales/tunings around the world would be most excellent. " That's kind of a lot to ask for--for a lot of reasons, not the least of which is that there are so many of them--Assuming that you are interested only in comparing Middle Eastern to Western stuff-even your Middle Eastern Singing class may not help you much--Turkish, Arabic, Persian, and Greek/Armenian music each use completely different pitch systems--so the same song, with the same notes, would have different pitches, depending on who was playing it--

UCLA used to have an Ethnomusicology site with recordngs of an Arabic oud player playing seven or eight different makams, which would give you a little to chew on, but I haven't been able to find it--