It is recognized by historians that the last song played by Wallace and his band was, "Nearer, My God, to Thee." This is one of 4 songs that witnesses documented being heard. It is possible (though not certain), that the band played more than one song as part of a final performance set. The other songs believed to have been heard were, "Bethany," "Horbury," and "Propior Deo." The latter two sound very similar, and the bands final set could have easily included one or the other.
Behtany, Horbury and Proprior Dio are all various tunes to which Nearer My God To Thee was set. The real argument musicians are having is HOW they played that song, which was not in their songbook, and unknown to most people except north American Methodists. The band was from the UK. A remarkably similar tune was Songe d'Automne, a hit at the time, and definitely in their onboard repertoire. From a distance it could easily have been mistaken for NYGTT.