See the description for the song which correctly points out:
This file contains the Banjo's standard musical notation and tablature for the song Soldier's Joy in the Key of C. This banjo version is in C Tuning (lower the 4th string to a C) and when playing with the mandolin and guitar player, Capo the banjo to the 2nd fret. This file is in tef. format with a computer generated midi file that can be heard with Tabledit's free viewer.
Song's midi file is in the Key of C
When capoed at the 2nd fret, the song is in D (where the guitar and mandolin play.
Just so everybody knows what my (Buck's) problem was with Soilders Joy, and I hope I'm right by saying it so we don't have to get taught again, is that I thought the midi version was to be played witht the capo on the 2nd fret, which, in C tuning would mean playing in the key of D, I think. The banjo midi version is in C tuning and written in the key of C and is to be played without the capo. So now my question is if I play the banjo with the guitar midi version do I capo or not. I gues what I'm asking, is the midi version for the guitar written in C or D?