mpflaga/Sparkfun-MP3-Player-Shield-Arduino-Library — pull request #1 by schottra (2012-10-19 17:34:10+00:00)
Title: Moving externs into SFEMP3Shield class

I have no way to test it, but I moved the externs into the class as static members. The C++ syntax is a little weird, but it compiles just fine, so it should run?