Elektra chord
The Elektra chord is a "complexly dissonant signature-chord" and motivic elaboration used by composer Richard Strauss to represent the title character of his opera Elektra that is a "bitonal synthesis of E major and C-sharp major" and may be regarded as a polychord related to conventional chords with added thirds, in this case an eleventh chord. It is enharmonically equivalent to a 7♯9 chord, D♭–F–A♭–C♭–E, and a 6♭9 chord, E–G♯–B-C♯-F. In the opera, the chord—Elektra's "harmonic signature"—is treated various ways betraying "both tonal and bitonal leanings...