Thanks for following my suggestion to split your original question...I
think it will work well for you.
Bits and pieces of information about Rose Landwehr -- who also went by
the name Rose Landver -- emerged from a search of the internet and of
archived newspaper records.
Although her name appeared in several papers, all the relevant
newspaper information below is from the NY Times.
I shall begin at the ending, with Ms. Landver's obituary:
Ms. Landver's obituary appeared in the Dec 2, 1981 NY Times:
ROSE LANDVER-DAVISON, 79,
OPERA SINGER AND TEACHER
...Rose Landver-Davison, an opera singer in Europe before World War II
and a former teacher of operatic acting, died Saturday at her home in
Rockville Centre, L.I.
...made her operatic debut as Rose Landwehr at the age of 19 in
Karlsruhe, Germany, and then sang leading roles at European opera
...marriage to...Jascha Horenstein, a conductor, ended in divorce in
1951. In 1960, she was married to Edward Davison, a poet and teacher
at Hunter...he died in 1970.
Surviving are a son, Peter Horenstein...
The earliest mention I could find dates back to 1931, and was not
Pfitzner's "Das Herz"
New York Times
Nov 29, 1931
...I shall waste few words over the first Berlin presentation of
Manfred Gurlitt's 'Soldaten,' which the Stadtische Oper brought
..The cast, headed by Hans Reinmar, Wilhelm Guttmann, Josef Burgwinkel
and Rose Landwehr, a guest from Dusseldorf, labored valiantly...
Numerous ads in the 1960's ran for The Hunter College Opera Workshop,
which listed Rose Landver as its artistic director.
Ms. Landver was also cited as the artistic director for a number of
Hunter College operatic and other productions. She also taught at the
Metropolitan Opera's Kathryn Turney Long School.
A brief mention in the March 14, 1940 NY Times, under "Music Notes",
mentions the appearance at the Hudson Park Branch of the NY Public
Library of "guest singer...Mrs. Rose Landwehr."
Another 1940 article (Feb 4, 1940) mentioned a performance at the
Museum of Modern Art, where Ms. Landwehr performed songs by Czech
composer, von Zemlinsky.
A June 5, 1952 'Music Notes' in the Times notes that "The Manhattan
School of Music summer school, Darrell Peter, director, has engaged
Mmm. Rose Landver as stage director of its opera workshop.
According to this link:
she directed Madame Butterfly, The Barber of Seville, and Amelia al
ballo in Philadelphia in the 1950's.
I trust this information provides enough material to pull together a
brief commentary on Ms. Landver's career.
Let me know if there is anything else I can do for you on this.
search strategy -- searched Google and several newspaper archives for
[ "rose landwehr" OR "rose landver" ]