Wagner composed this "Symphonie" (so called on the title page of the autograph score) in 1870. Siegfried Idyll was both a birthday and a Christmas present for the composer's bride of four months, his mistress for seven years before that, and the mother of his three illegitimate children � Isolde, Eva and Siegfried (a.k.a. "Fidi"). She was Cosima, herself one of three illegitimate children sired by Franz Liszt during his 11-year liaison with la comtesse Marie d'Agoult. Young enough to be Wagner's daughter, she survived him by nearly 50 years, and with a mailed fist controlled the Bayreuth Festivals as well as his musical legacy until her death in 1930, at the age of 92.

The Idyll (originally called Triebschen-Idyll with Fidi-Birdsong and Orange Sunrise) was first played on Christmas morning on the staircase of their Swiss villa by 15 musicians from Lucerne. Wagner published it eight years later because, as usual, he was deeply in debt, despite appropriating other men's money, connections, wives, whatever, without scruple, remorse, or intention of repayment. No one was exempt from his machinations � not even monarchs. The pianist and conductor Hans von B�low (a prized pupil of Liszt), who was Cosima's first husband, had transferred allegiance to Wagner, who rewarded him by stealing his wife and living openly with her in Munich. Even so, B�low premiered Tristan und Isolde and Die Meistersinger there before Wagner's and Cosima's scandalous flaunting of convention forced King Ludwig II (another gull) to banish them in December 1865. By way of Vevey, the lovebirds went to Tribschen (Wagner coined the alternative spelling), home for them until their move to Bayreuth in 1872. Cosima professed surprise as well as joy when she first heard Siegfried Idyll, although she knew it was being composed, and had even heard snatches of it in rehearsal. All but one of the principal themes in sections 1 and 3 came from a string quartet Wagner sketched but never finished in 1864, the year they first cohabited. The work begins and ends in sonata form, with the exposition and recapitulation of three themes. A "central section" occupies 201 of the Idyll's 405 measures, with its own central section � three new subjects from the opera Siegfried: a horn call, a triplet figure, and birdcalls. The E major main theme of the exposition, beginning in measure 5, is worked over until clarinets introduce a B major second theme in measure 56. The oboe plays a third theme in measure 91, also in B, adapted from a German lullaby Schlaf', Kindchen, schlafe. But we don't hear this again until the recapitulation, just before a coda that recombines subjects 1 and 2. Despite the small premiere ensemble, Wagner meant the Idyll to be played by more than seven strings and often conducted it at orchestral concerts later on.

This arrangement is for string quartet with an optional bass part.