Oscar Wilde’s late plays and stories, so un-politically correct and obsessed with death, proved rich pickings for composers and librettists at the beginning of the 20th century. If no one got it quite as ‘right’ as Richard Strauss in Salome, Zemlinsky was able to make powerful musical theatre out of A Florentine Tragedy and The Birthday of the Infanta, the latter becoming Der Zwerg (‘The Dwarf’) in librettist Georg Klaren’s softening-up expansion.

So although this makes for a well-performed programme from March 2019 in Berlin, it cannot match the cruel beauty of Wilde’s original fairy story, either in its writing or its dramatic realisation here. The issue of how to make up a full evening’s theatre from a single work of (as here) just over 80 minutes’ playing time is cleverly solved by stage director Tobias Kratzer. He presents his research on the autobiographical nature of Zemlinsky’s opera by staging its apparent motivation – the failed love affair of the composer and Alma Mahler soon-to-be – as a music lesson with Alma and Zemlinsky as flirting pianists. His clever choice of music (just over eight minutes), in which both performers play the extended piano parts, is Schoenberg’s enigmatic Music for a Film Scene, which proceeds into the opera without interruption.

The opera staging itself follows a currently obsessive German trend: everything is set in modern concert dress in a featureless white room, here perhaps a concert hall with busts of artistes. Kratzer’s second coup is less successful and weakens some of the grotesquerie of the drama – his staging shows two ‘dwarves’, one an actor of restricted height and the other a tall and conventionally handsome singer, who takes an increasing role in the action. If you know the plot, you can predict a big shock will come when the actor sees the singer for the first time through a mirror. An iconic moment, certainly, but not enough to compensate for dramatically wasted – and wrong! – time in which scenes between the Infanta (a pity that she looks older than Wilde’s young teenager) and the Dwarf resemble any conventional lovers’ meeting. Also the sympathy shown for the Dwarf by Ghita, the favourite courtier – movingly acted here by Emily Magee – is much reduced in emotional effect when directed at the singer Dwarf.

Runnicles, his players and his cast have obviously used their rehearsal time on these difficult scores to maximum effect. The orchestra play their difficult cues like angels – the part-writing sounds like a less harsh Mahler but is still super-demanding in its virtuosity and colour. The staging is similarly tightly rehearsed, the filming and recording excellent. It’s just a pity that the effect of all this effort is to weaken the creepy (and freaky) strength of Wilde’s drama.