Does playing music substantially kill phone battery life?

I have the Optimus V, from Virgin Mobile.

I run Android OS 2.2.

I've been toying with the idea of replacing my ipod with a fat SD card for my phone.

What I'm worried about is battery life.

Currently, my charge barely lasts a full day of semi-extensive use.

With low use, I usually end with about 20-30% battery.

Anyone have any advice from personal experience with music playing on mobile phones similar to my situation?

Any input would be greatly appreciated.

Thank you reddit.