I told you but surprised that you cannot say the same for her sister. I've seen written testimonial given by Professor Theremin as to her abilities.. ?

@FrayedBear I don't doubt that she is highly skilled. Just saying that for that piece of music, I don't care for the sound of the instrument. It's not bad, and I'm hopeful of finding an application of the instrument which I can wholeheartedly endorse. And I really did find the sense of timing of the pianist's well applied rubato (the subtle slackening and quickening of pacing, for any viewers of this who might be unfamiliar with the term) highly expressive, as I did also find her nuance of touch ranging from softer, to louder, and in between.

@Rossy92 You are talking of physical ability on a piano compared to that on a theremin where the notes are produced not by depressing a given key but by continual tuning by the performer of each note played through having perfect pitch and extraordinary physical ability as each note played requires precise placement of the hand with no black and white keys or frets to guide the player. An instrument where an unplanned shrug of the shoulder will result in an out of tune note. Just as piano volume control on the piano is controlled through the speed of the hammer hitting the strings, equally volume control on the theremin requires constant adjustment of the hand through the looped aerial

@FrayedBear Your description gives me a greater appreciation for the skill involved. But ultimately the end result is what counts. How many virtuoso wizards fail to be able to communicate with a feeling which touches the listener. I acknowledge that the level of difficulty is high, and I don't even fault the instrumentalist for any shortcomings. I feel the limitation resides in the instrument itself. As I indicated before, perhaps there are other works of music which better exploit the theremin's unique tonality and capabilities.

@Rossy92 Personal preference is always highly subjective. I merely thought the "Vocalaise" best suited this group as an introductory piece to showcase the Theremin and two artists.
The instrument btw has a 5-octave range and probably can be described as the grandpappy of all the Moogs and electronic organs/pianos that were ultimately to be created.

@FrayedBear You seem not to have noticed I gave the post a "like".

@Rossy92 ? Don't worry. I'm just having a hissy womanlike snowflake moment!

The cd that piece is taken from is Delos D/CD1014 ©1987 "The Art of the Theremin" which came with an excellent booklet that includes an electric schematic of the 1937 RCA theramin of which 200 were built. The CD was later re-released under licence by Naxos.
Amazon have another recording called the "Lost Theremin Album". EBW writes a sound review and points to a third cd.

@FrayedBear Thank you for the info. I will look for them