[*Petit*]

I've never heard of 8/4 but it would sure be the same as 4/4, unless there's some rhytm or theme repeating each 8 beats. 4/4 us used for almost all popular and non popular music that could fit inside the "pop" (including all rock, dance, trance etc) styles. 3/4 is a waltz or menuetto depending on the rythm. 6/8 is also used for waltzes. In humming it sounds to me like it's mostly 4/4, except for the very last part of the bridge and some other places, but I don't know which ayu songs are what because I haven't seen any official sheets. These numbers are only used to make it easier for the mucisians, and the same rythm or passage can be made using different signatures, marks etc.