Secure Digital Speed?

I'm interested in buying a SD card to play music and other audio files on my Palm Tungsten T. I've had the Tungsten for several years and this will be my first experience with a memory expansion card. I'm pretty certain I will only use it to store and play music, since I've had the PDA for this long and haven't had a need to expand the memory.

With that said, how important is the speed of the card when it comes to playing music? I've seen a lot about write-speeds for taking pictures with a digital camera, but I suppose read speed would be more of a factor for playing music.

I'm looking for a 512K card and there are some that are very inexpensive, but as usual, you get what you pay for. So I'm wondering what I should be looking for in a card that will mainly serve as a source to store/play music.

TIA.

Tipsy