Thanks for that link - It shows the Pinout for an Arduino Uno to run the MP3Shield Library.
Unfortunately the link to the vs1053 datasheet gives a 404 not found -http://www.vlsi.fi/fileadmin/datasheets/vlsi/vs1053.pdf
I have found the full ESP32 WROOM datasheet online however - https://www.espressif.com/sites/default/files/documentation/esp32-wroom-32_datasheet_en.pdf
Hmmmm.....