I seem to be haunted by musical things today. Posting those videos reminded me of violin lessons when I was little. I was terrible -- uncoordinated and untalented -- but I stayed in orchestra through junior high school, which was long enough to appreciate what a good violin should sound like in the right hands.

The E string of a violin is something you could use in a deli to slice hard cheeses, being a very thin steel string and pulled so tight it used to cut my fingers up. You have to press so hard on it to push it down to the fingerboard to make the note. I didn't practice enough to toughen my fingertips.

One of my favorite musicians, Jascha Heifetz, played those high, high notes on the E string as if it were the easiest thing in the world. I think either Goldmark or Korngold composed pieces so he could basically show off his skill with high notes.

I think violin is the hardest instrument to play. Unlike the guitar, there are no markings to show you where to place your fingers to make the notes. I guess this is because you can change the violin's notes -- where on the strings they sound -- by changing the tuning, changing how tight you make the strings. I've heard of violins tuned deliberately to alternate notes in order to play certain compositions. Of course you could do it to any stringed instrument, like on a guitar, rendering the chord markings irrelevant.

Maybe another free-form instrument equally hard to play might be the Theramin. You're playing by moving your hands in the air way above your instrument, and you have to move very, very precisely or else it just sounds like gibberish.

My first violin teacher was also the orchestra teacher in junior high. One day when everyone was just coming into class and sitting down, he picked up his violin and suddenly burst out with a passage I recognized. It was the theme used at the start of a radio program that played on Sundays, about 45 years ago, a program called Gypsy Trails. I can whistle the passage, sort of. But I've never found out what piece of music it's from. Kind of an athletic piece. Perhaps with help of YouTube I'll find out eventually what it is.