I have been called a "fount of useless knowledge" by family and friends alike. But reading encyclopedias cover-to-cover as a child does have its advantages - I can produce strange posts like this one. Today is the last day on the theme of musedom; tomorrow will be about the mind and the brain.
Beethoven's "Immortal Beloved" from that famous passionate letter ("my angel, my all, my very self") is suspected by some to be Antonie Brentano, the wife of Franz Brentano, who was the brother of Clemens Brentano and sister of Bettina Brentano von Arnim, herself an artist remembered for her association with Goethe. Clemens and Achim von Arnim (yes, Clemens' brother-in-law, but post-publication) are responsible for Des knaben Wunderhorn (Youth's Magic Horn), a collection of German folk stories published in 1805.
Nearly ninety years later, Gustav Mahler wrote songs to several of the poems contained in that work; two of the most memorable are St. Anthony of Padua's Sermon to the Fishes (Des Antonius von Padua Fischpredigt) and Primeval Light (Urlicht), both of which would be incorporated into the third and fourth movements, respectively, of Mahler's 2nd Symphony. An aside: the funeral of Hans von Bulow, the famous conductor and pianist and cuckold to his former wife Cosima Liszt and former cherished friend Wagner, helped to inspire the fifth movement of Mahler's 2nd Symphony in its themes of resurrection.
After Mahler's death, his wife Alma eventually became re- involved with the Bauhaus architect Walter Gropius (they'd had an affair while Mahler was still alive), with whom she had daughter Manon Gropius. Manon's sudden death at the age of 18 inspired Alban Berg to compose his Violin Concerto To the Memory of an Angel in 1935 (by this time, Alma was married to Franz Werfel). [I've never seen Bride of the Wind (2001), named after Kokoschka's Alma-inspired painting.]
Fifty years later, Jerome Robbins choreographed a ballet to that music, titled In Memory of... with Suzanne Farrell in the lead part. Even though Robbins denied that it was in memory of anyone specific, the title, timing, and Robbins' choice of Farrell, considered to be the greatest and most cherished muse of his NYCB colleague, left no doubt for most people that it was in memory of...of course, Balanchine.
In both 1969 and 1977 Balanchine had made plans to do a ballet for Farrell, casting her as Salome (their relationship made this casting a bit hmm, questionable; Stravinsky had joked to Robert Craft about how much clothing this Salome would shed) to music from Berg's Lulu Suite. I don't know Balanchine's thoughts on Mahler, but I do know that according to ballerina Violette Verdy via dance critic Robert Garis, in an encounter in the sixties that she arranged between her friend Pierre Boulez (that enfant terrible of the classical music scene) and Balanchine, hoping that their mutual passion and knowledge of music would create some rapport and fascinating insights at her dinner party, Boulez did all the talking, and Balanchine did almost none. How is that related to Mahler, you may be wondering? Well, Boulez is a noted Mahler lover and gets a verbal "thank you" near the end of the third movement of Luciano Berio's 1969 work Sinfonia that directly alludes to Mahler's "St. Anthony and the Fishes" music. Quite the stretch, I know.
And to take this chain full circle, Balanchine considered Beethoven's music "not danceable." In Balanchine's view, only three composers: Stravinsky, Tchaikovsky, and Glazunov, wrote "danceable" music, in the sense that it was meant to be danced to, in rhythmic pulse. Balanchine did choreograph works to Gluck, Bach, Mozart, Schumann, Bellini, Bizet, Mendelssohn, Ravel, Webern, Ives, Gershwin, and many others (he didn't choreograph more than 430 works to the same music over and over again), but considered Beethoven wonderful music to be listened to, not danced to.