Pass audio from input line to speaker output with Mp3 Shield VS1053 - Programming Questions - Arduino Forum
MP3 Player Shield Hookup Guide V15 - SparkFun Learn
MP3 Player Shield Hookup Guide V15 - SparkFun Learn
Buy MP3 Player VS1053 Shield - Shield for Arduino Botland - Robotic Shop
GitHub - madsci1016/Sparkfun-MP3-Player-Shield-Arduino-Library: A nice and neat library for playing MP3s on your Arduino using Sparkfun's MP3 Player Shield
Adafruit "Music Maker" MP3 Shield for Arduino w/3W Stereo Amp (v1.0) | The Pi Hut