"Proper" worship music

Does anyone have any thoughts about what constitutes "acceptable" worship music? As I was walking Tip this early AM and listening to "Smile FM" I mused about how some folk seemed to harbor disdain for anything other than the "standard" hymns as acceptable within that guarded Sunday hour. I wonder the view held by the contemporaries of the original composers of our older hymns, (Crosby, Wesley, et al)? Were not these composers writing from their heart felt stirrings? Are those stirrings any different then those of the modern composers?