i've got a dv6 and the memory it came with was not enough for day to day use so i upgraded the memory which is quite cheap. if i remember rightly there are only two memory slots so you will need 2 x 4 mg memory modules to take it up to 8 gb although i only added one 4meg so i've got 6 meg which is a bit odd but works much better.

i don't use it for music but the installed memory was a bit light for everyday use so i think videotrack is right about your RAM being a bit tight.