Playing a music with an arduino uno

the wave shield is a shield for the UNO and does mono sound. It uses SPI port to read the WAV sound files on the SD card and bit bangs the digital sample data to the on-board serial DAC using 4 other pins and it has a speaker output.

Any ideas on how to do something similar but instead of output samples data to DAC output to Blutooth module for link to Bluetooth speaker........