Step 1: Why Does This Music Stand Fail?
Answer: Cheap parts, misuse, overuse, and poor fastening.
The bolt that connects the base of the music stand to the shaft, has too much lubricant on the threading. Although it initially allows for easy assembly, it also allows the bolt to back out of the shaft.
[see picture #1]
The pivot section of the music stand (in back of the music stand's face) relies on inferior washers, which slowly deform from regular use. The deformity of these washers causes a lack of tension, which then causes the face of the music stand to sag (this is why your music keeps falling down). Also, the inside of the nut may not have a nylon component, which allows the nut to back out at times.
[see pictures #2 and 3]
The connection between the shaft and pivot will sometimes slip out. Overtightening can deform the apparatus, so I will suggest using epoxy and a nylon nut instead.
[see picture #4]
Students are to blame for most of the wear and tear. They stand on top of the music stand base, wiggle it around, constantly adjust the face, etc. Students will have a difficult time destroying your music stands after this instructable.