Love, in Gottfried von Strassburg’s version of Tristan and Isolde, is exalted beyond all else. It transcends earthly confines such as marriage – and even life itself. Inextricably linked with both joy and sorrow, love is a noble goal, the pursuit of which justifies all means.

It is this version of the legendary romance on which Wagner based his now renowned opera. And perhaps his choice of text is somewhat autobiographical; at the time of writing Wagner and his wife were staying on a friend’s estate, and the composer had become infatuated with the lady of the house. While the full extent of their relationship is not known, its passion not only caused a rift in the composer’s marriage, but almost certainly fuelled his creative spirit.

The opera’s Prelude – Vorspiel – begins with a simple cello phrase before landing on what has become a musical icon – the famous ‘Tristan’ chord, whose ambiguous dissonance is said to signal the beginning of the end of tonality. In Tristan und Isolde this unsettling chord returns in various forms throughout the work, underwriting the tension that propels the opera’s narrative.

Isolde’s Liebestod closes the opera, but in the concert hall version it immediately follows the Prelude. Tristan lies dead in Isolde’s arms, having being mortally wounded by a knight who has spied the couple ‘s secret rendezvous. Sweetly poignant melodies rise up as Isolde imagines her beloved still living. But despair soon takes hold, and Isolde wills herself out of existence towards the ‘utmost bliss’ of death.