This is a driver library for Seeduino Music Shield V2 http://www.seeedstudio.com/wiki/Music_Shield_V2.0 Original library is too reusable, and non flexible.
This lib use standard SPI library. For play mp3 and another formats with big bitrate (for 8-bit chip) I recommend use SdFat lib. Example contains sketch with LCD display and SdFat.