LED lights can be up to 15 times brighter than a regular incandescent bulb, according to EarthEasy.com. They also are visible from farther distances. Although this is beneficial in that LEDs require much less electricity, you have to keep in mind that music stand lights are not supposed to distract from performances. They should be bright enough just to see the music well. Thus, choose a very low brightness when selecting an LED.
Because all performance settings are slightly different, you'll want to put a neck on the music stand light that is completely adjustable. This will let you bring the LED down over the music stand and position it so it shines in an optimal way on your sheet music. The easiest way to get a safe neck on your lamp that will adjust is to use a lamp cord (the same kind used in droplights) covered by some flexible rubber tubing (insulate).
Ideally, your LED music stand light will operate on a battery pack instead of having to connect to an electrical outlet. This reduces the risk of tripping on cords and having your stand overturned by accident, especially in tight performance quarters. You can purchase battery packs from Radio Shack or other electronics stores such as Best Buy, but you have to be sure to get the pack that matches the voltage for the LED. Otherwise the LED won't operate. If you make your own battery pack, enclose it in hard plastic and screw the pieces of the pack together.
When picking the clip that will hold the LED lamp to your music stand, larger isn't always better, because you'll want to be able to transport the light easily. However, DO pick a clip that has a very strong spring. Thin springs will wear out much faster and won't have the ability to lock the lamp tightly on the stand.
Screws and hot glue can be used to connect most of the parts of your lamp. An easy assembly design is to connect the LED bulb to the lamp cord and rubber insulate, attach the battery pack to the other end of the cord and insulate, and glue or screw the battery pack to the clip. Then you can put on a plastic guard to protect the bulb.
Concert etiquette dictates black clothing and stands for performers if possible, and again, the lamp shouldn't detract at all from the performance. Stick to black plastics and tubing and choose white for the bulb color unless this is too harsh on your eyes (use very light blue in this case).