Amyotrophic lateral sclerosis (ALS), sometimes called Lou Gehrig's disease, is a rapidly progressive, invariably fatal neurological disease that attacks the nerve cells (neurons) responsible for controlling voluntary muscles.
The Alpine Scheitholt furnishes an example of this older type of European zither. By the late 18th century, two principal varieties of European concert zither had developed, known as the Salzburg zither (with a rounded side away from the player), and the Mittenwald zither (with both sides rounded).
Now you have to get together with two or three of your zither-playing buddies and get everyone's instrument in tune with each other's so you can form zither trios and quartets. For these ensemble purposes, they even make different sized and pitched zithers - like the quint, tuned a fifth higher than the prime zither, and the elegy, or alto, tuned a fourth below the prime.