How about this? You set the BPM, the sheet music starts with the first measure in the middle in a little highlighted pane, after enough beats the measure advan

How about this? You set the BPM, the sheet music starts with the first measure in the middle in a little highlighted pane, after enough beats the measure advances and the second measure is in the highlighted area. And you can have a metrnome ticking too. Maybe a visual cue of how many beats are left in the measure for a "silent practice" mode. It'd be tricky if you have a changing tempo though.