Assign one instrument to two staffs
I am having a problem with MuseScore importing PhotoScore XML. The PhotoScore XML for an SATB plus Piano score specifies 6 score-parts. One each for S, A, T, & B and two for the Piano (one for the Treble staff and one for the Bass staff). MuseScore creates a score with 6 staffs -- one for each score-part. How do I get MuseScore to treat the two piano staffs as a single instrument?