Thus Spake Zarathustra is Richard Strauss’ most recognisable work. But what ideas lurk behind the fanfare?

The greatest melodies, the kind that transcend centuries and transport us to the greatest heights, are often the simplest: Ode to Joy springs instantly to mind. That immortal tune bursts forth in the final movement of Beethoven’s last symphony; Richard Strauss’ orchestral tone poem Also Sprach Zarathustra, seven decades later in 1896, shocked listeners with the force and stark immediacy of its first five notes. One hundred and fifty years after its composer’s birth, that five-note ‘Sunrise’ fanfare remains one of the most powerful and recognisable moments in classical music — and not just because of its striking use in Stanley Kubrick’s film 2001: A Space Odyssey as the sun peers over Earth. Strauss’ blazing sunrise, musically and philosophically, ushered in the dawn of a new era. The composer himself was all too aware of his place at the crossroads, originally intending to subtitle the work: ‘Symphonic Optimism in fin-de-siècle form, dedicated to the 20th century.’

Of course, there is more to Zarathustra than those first triumphant two minutes. Strauss based this controversial yet popular work on Friedrich...