Leon Theremin interview, Lev Sergeivitch Termen interview, Olivia Mattis

"I played Glinka's "Skylark", which he loved very much, and Vladimir Il'yich said, after all this applause, that I should show him, and he would try himself to play it. He stood up, moved to the instrument, stretched his hands out, left and right: right to the pitch and left to the volume. I took his hands from behind and helped him. He started to play "Skylark". He had a very good ear, and he felt where to move his hands to get the sound: to lower them or to raise them. In the middle of this piece I thought that he could himself, independently, move his hands. So I took my hands off of his, and he completed the whole thing independently, by himself, with great success and with great applause following. He was very happy that he could play on this instrument all by himself."