Valentine's Day—Alma's Theme from Mahler's 6th

Alma Mahler related how during the composition of his 6th symphony, Gustav brought her to his composing hut one day to play the theme she had inspired, saying: I've tried to capture you in a theme – as for whether I've succeeded, I don't know. You will have to tolerate it.' 

Each repetition of the theme is increasingly passionate and harmonically complex, until it bursts through to a quiet Arcadian pastorale over a drone of F and C. This moment in Mahler's 6th seems to actually reference Beethoven's 6th "Pastoral" symphony, also in F major with an F-C drone. But the glorious hyper-romantic theme itself, with its wide range, chromaticism, rich 9th and 11th and 13th chord harmonies—that is all Richard Strauss, isn't it?