i can't stand music which is too loud.which表达什么意思.

i can't stand music which is too loud.which表达什么意思.
which是关系代词,代替前面的music,在定语从句中当主语.那为什么要用which不用that呢可以用that那什么时候用which呢当先行词表示物，且在从句中当主语或宾语时，用which和that没有区别。只是当先行词有比较级、最高级、序数词等时，用that。