Leonard Cohen’s Hallelujah on a glass harp — crystal glasses filled with different amounts of water — played beautifully by a street musician in Prague. You can see and hear more of his work here and here.
I remember by accident keeping my TV on PBS one morning after The Electric Company finished and heard the announcement that someone was going to play the glass. I was 10, I sat there in awe. When it was over I immediately ran to my mother’s china cabinet and filled her crystal glasses with water. I was pleasantly surprised when I was able to make a sound. I spent all day (about 7 hours) adjusting the water levels trying to play Mary Had a Little Lamb. By the time my mother got home that evening, I was ready to play a concert for her. What a feeling of accomplishment I felt because I stuck with it no matter how frustrated I felt. She could not believe it and said, you see you could do anything if you put your mind to it. Music teachers, watch with your students, let them figure it out themselves and plant the seeds of determination and perseverance.