Operation Tannenbaum Operation Tannenbaum Operation "Tannenbaum ("Fir Tree"), known earlier as Operation "Grün ("Green"), was a planned but cancelled invasion of Switzerland by Nazi Germany and Italy during World War II. For tactical reasons, Adolf Hitler made repeated assurances before the outbreak of the Second World War that Germany would respect Swiss neutrality in the event of a military conflict in Europe. In February 1937, he announced that "at all times, whatever happens, we will respect the inviolability and neutrality of Switzerland" to the Swiss federal councillor Edmund Schulthess, reiterating this promise shortly before the Nazi invasion of Poland. These were, however,
Weihnachtsbaum (Liszt) have been intended for some collection". This latest version of "Schlummerlied" was first performed at the Aeolian Hall, New York, on 12 November 1921, by John Powell. The first recording of Liszt's "Weihnachtsbaum" was in 1951, by Alfred Brendel. This was also Brendel's own debut recording. Later recordings are by France Clidat, Leslie Howard, Rhondda Gillespie, Roland Pöntinen, Eteri Andjaparidze, Jerome Rose, Pietro Spada and Olivier Vernet. Excerpts have been recorded by Ilona Kabos, Stephen Hough and others. The version for piano four hands (S. 613) was recorded by Roberto Szidon and Richard Metzler. In 1952 Anthony Collins arranged four