These days most cell phones double as am MP3 played, and the straight talk phone is no exception. Adding music to this phone can be tricky, however, as most straight talk cell phones don't come with a USB cord, only a cell phone adapter. There is a simple way around this problem though. You can add music to your phone the same way you add ring-tones, only without the hassle of needing to change the file type.
Remove the microSD memory card from your phone by pushing down on the card gently, then pulling it out. Place the card in your phones adapter, then plug it into your computer.
Navigate to "My Computer" then double click your phones microSD card from the list of devices. You will now see several files on your phones memory card. Click on the one named "My Music."
Copy and paste the music files you want on your phone into the "My Music" folder. When you're done, disconnect the device by right clicking on the "Safely Remove Hardware" icon next to the clock on your computer, then removing the device from the list.
Navigate to "MultiMedia" on your phone, then "My Music." Here you will be able to see and hear all of the music you just added.