This was pretty simple. With the lid opened, I measured the keyboard opening, found its center and marked it on the inside lid about an inch up from the bottom. I then measured the length of music desk, found its center, marked it. After marking 1" up from the bottom of the lid in several places where the desk would be placed, I applied a generous amount of glue to the desk and matched the center mark for the keyboard opening with the center mark on the desk, being careful to line up the bottom of the desk with the 1" marks so the desk would be level. I clamped it on both ends, mopped up excess glue that squeezed out, and called it done.
Of course, it is possible to glue the desk on incorrectly, but I managed to get it right. The stack of National Geographic Magazines was eventually piled on the center since I only had two clamps handy. Had my life partner been around, he might have suggested Karl Barth's Church Dogmatics, but the magazines did the trick.
From another angle:
Next step is to stain the cabinet. I'll post a few pix as it progresses.
