Complex sentence: Six years later, in 1922 the standard edition was published, more strongly based on the "old complete edition" than the less popular "new and revised edition", this also was edited by Nicholson who was the musical editor until he died in 1947.
Split into simpler sentences: Six years later, in 1922, the standard edition was published, more strongly based on the "old complete edition" than the less popular "new and revised edition". This also was edited by Nicholson, who was the musical editor until he died in 1947.