Luis, It's not a mistake to lift your thumb up in the higher positions. It actually makes it easier to get a good vibrato that way. Nobody on a jury would consider that a mistake as long as the player gets a good sound. Many of the "rules" we learned as students are not so much rules as they are guidlines to be used or discarded by the seasoned performer as he sees fit. What was nessesary for a beginner learning his instrument is not longer a hard and fast rule once he has conquered the technique of playing his instrument.
Luis,
It's not a mistake to lift your thumb up in the higher positions. It actually makes it easier to get a good vibrato that way. Nobody on a jury would consider that a mistake as long as the player gets a good sound. Many of the "rules" we learned as students are not so much rules as they are guidlines to be used or discarded by the seasoned performer as he sees fit. What was nessesary for a beginner learning his instrument is not longer a hard and fast rule once he has conquered the technique of playing his instrument.
what grade???
Great sound but your thumb come off very often when you go higher up. Still great but in a technique competition that is a big mistake.