This is far into Music Cloud's time in the dataverse, but I have discovered another failure includes that Classic Smart Music did rather nicely, PLAY DUET PARTS separately from the Rubank Advancedbooks.  Very strange when they have the accompaniment for other tunes and solos, but cannot do the separate duet parts?  Another teaching tool discarded.  Also noted that a good many of the exercises are set at 144 BPM whether that is logical or not.  Anyone else out there looking at this?