I was first introduced to Clara Rockmore when browsing videos of students playing video game themes on the theremin (wiki
). The theremin, by the way, is the only instrument that requires no touch. It senses when you are close. Bringing your hand closer to the vertical antenna makes the pitch higher. Bring your hand towards the horizontal antenna makes the pitch softer.
Here's a video of Leon Theremin playing the instrument he invented.
Clara Rockmore entered St. Petersburg Conservatory at age 5, as a student of the great Leopold Auer, earning the prestige of being the youngest student ever accepted. Later on in her teens, after developing some sort of muscle condition, Clara dropped her violin career in favor of the theremin. She worked directly with Leon Theremin to make certain adjustments to his invention, and developed a fingering system similar to what we call "positions" on the violin. What fascinates me about the theremin, is that portamenti (use interchangeably with "glissando"), or slides, are built in to the instrument. It is almost impossible to avoid them, especially as you change hand positions. The portamenti are a fundamental characteristic of theremin sound and they are necessary for maintaining a sense of accurate pitch.
When playing the violin, students these days are often told to avoid portamenti altogether, or to only slide occasionally. Portamenti are often regarded as distasteful, self-indulgent, or dirty. Extremely sterile playing is regarded as a virtue, especially in an orchestral setting. Clara Rockmore's theremin playing has made me rethink the use of portamenti in my own violin playing. After all, the violin has no frets. Before Spohr, and the invention of the chinrest, the portamento (slide) was a much more necessary aspect of violin playing. After much thought on the subject, and reading Ruggiero Ricci's treatise on the subject (Ricci on Glissando: The Shortcut to Violin Technique), I firmly believe that portamenti (glissandi), should play a more commanding role in violin technique. As a side note, some musicians make an effort do differentiate between portamento and glissando, though physically, the left hand action is identical. Should we sound like cats mewing? Hopefully not. Portamenti should sound "vocal." Also, a delicate glissando can be used as a vehicle for great listening and great accuracy, especially in double stops and in virtuosic passages.
My favorite Clara Rockmore video is the "Hebrew Melody" by Achron, a 20th century composer know for his film music. The portamenti in this piece sound weeping and full of sorrow.
I was so moved by this performance, that I decided to play the "Hebrew Melody" for my public recital last year, taking a shot at producing a similar a similar affect on the violin.