Tourists who go to Nuremberg in Germany are mostly there to stroll around its timber-framed medieval houses, visit Albrecht Durer’s studio, and (if musical) remember Wagner’s Mastersingers.

Ham & High: Laurent Naouri and Guillaume de Chassy perform A Song of Good and Evil. Picture: Arne HyckenbergLaurent Naouri and Guillaume de Chassy perform A Song of Good and Evil. Picture: Arne Hyckenberg (Image: Arne Hyckenberg 2014)

But a few of them – and I’ve been one – search out a still intact, still functioning court room.

It was there, in 1945/6, that the famous post-war legal process of the Nuremberg Trials happened.

And although they have no obvious musical significance, there’s an intriguing minor fact about those trials that Hampstead lawyer Philippe Sands has made the basis for a sort of play-with-music running at Kings Place in May: “A Song of Good and Evil”.

Two men locked in conflict in that courtroom – one of them a prosecutor called Hersch Lauterpacht, the other a defendant, Hans Frank, sometime Nazi governor of Poland – separately took refuge from the tensions of the trial by listening to the same work, Bach’s St Matthew Passion.

Frank was listening in his cell as he awaited judgement (he was ultimately executed), Lauterpacht was listening more comfortably in a hotel room; and presumably the music spoke to them in different ways, albeit with the same result.

But there were other aspects of their lives shared by these two men.

Both were lawyers of some eminence.

Lauterpacht’s family had been wiped out under the Frank regime in Poland. All of which helps to explain why Sands was drawn into their story.

Well-known as a practising QC and academic, with a chair at UCL, Sands’ speciality is public international law.

He’s been involved with prosecuting the ex-President of Liberia, Charles Taylor; with defending Guantanamo Bay detainees; with arguments for holding Bush and Blair legally accountable for the unlawful invasion of Iraq. And he has a professional interest in Lauterpacht who went on to become a celeberated jurist responsible for developing the concept of ”crimes against humanity”.

But Sands is also Jewish, and has family who perished under Frank in Poland in the 1940s. Looking back at what took place there, from a lawyer’s point of view, has turned into a mission.

He made a film for BBCTV, shown last month, about travelling through Poland with the son of Hans Frank.

And it was a lecture that he gave at Oxford about Lauterpacht and an associated Jewish jurist, Raphael Lemkin (who invented the term “genocide”), that turned into the basis for the piece running at Kings Place.

Sands describes it as a “dramatised lecture…semi-staged with video projections, film and music”. Nina Brazier directs a group of narrators, actors and musicians that include Sands himself and the celebrated French baritone Laurent Naouri.

“Laurent is a friend from childhood”, Sands explains, “as well as a very fine singer; and I can only say I’m overwhelmed by the power of the music in this show.

“I’ve done it a few times before – starting with a trial run in the Hay Festival in 2014, and then places like Stockholm, Toulouse, Istanbul, and the Nuremberg courtroom itself: that was last year. And always, the music really gets to me.

“I’m a litigator. I’m used to standing in front of international tribunals with twenty judges, and I do it without fear. But being on the platform with Laurent is the most fear-inducing, challenging, exhilarating and exciting thing I’ve done. I’m not a musician, but I love music. And it makes all the difference here”.

As to the choice of music, it unsurprisingly involves extracts from the Matthew Passion, but with other things besides, chosen for their relevance to the characters, story and times.

Of special interest is a song, written in honour of Hans Frank by Richard Strauss after Frank did him the favour of exempting his house from wartime requisition as a refuge for evacuees. It was presumably intended as a joke – they knew each other – and it doesn’t make Strauss an apologist for the Third Reich: he was no Nazi, just an old man uncourageously keeping his head down during tough times.

But as Sands says, in the light of history it showed poor judgement.

And as Strauss’s words survive alone, without the score, “A Song of Good and Evil” will present them packaged in new music. As a curiosity.

A Song of Good and Evil plays Mon 16 & Wed 18 May, 8pm, Kings Place N1. Booking: kingsplace.co.uk