I type in all the chords, pick a style, go to tracks, generate, etc, exactly like the video tells us to do. When I click play, all that comes through is the drums in the 1st track. When I try to add another instrument to any other track it says "Song doesn't override real tracks on this track". What needs to be done? And, would someone please tell me, step by step, how to accomplish that? Thanks so much. Zeke.