Depends on what range is that "today" meaning, but this instrument (called
the Theremin, which is also the name of its inventor), was used
extensively in 50's scifi/horror movies, and
I know that Jean-Michel Jarre used it live in the 80's.
Jean-Michel Jarre? Are you talking about '80 of the '800?
That's not today in any way!
Ok, just kidding!
Did Jarre still played the Rachmaninoff as Clara Rockmore or did he
re-arrange it another time?
Ok, still kidding!
It's too easy to laugh on Jarre... not a great contribution. Sorry.
I think Kiilo meant to compare the relative stability of the traditional
instruments to the way we are still working today with electronic
devices. Theremin may be still in use and have influenced many other
interfaces to electronic devices but sure it is not a well established