The long-running series in which readers answer other readers’ questions on subjects ranging from trivial flights of fancy to profound scientific and philosophical concepts

• This week’s question: Why is a child saying ‘Na-na, na-na-na!’ so annoying?

Why are national anthems almost always orchestral? When – and by whom – was it decided that brass and strings best represent a country’s identity? Where are the power-pop or folk varieties? Ross Gomes, by email

Send new questions to nq@theguardian.com.

The choir leader and presenter on not fitting in at his all-boys grammar, how synthesisers changed everything, and his ‘dithering’ start on TV

Born in London in 1975, Gareth Malone is a choirmaster and broadcaster. He began his career running youth and community choirs for the London Symphony Orchestra and first appeared on TV in 2006’s The Choir. He has since created choirs with Leicester schoolboys, Aylesbury prisoners, as well as the Military Wives, which produced the No 1 single, Wherever You Are. He lives in London with his wife and three children. His new live show, Sing-A-Long-A-Gareth: At the Movies, is on tour across the UK this autumn.

I was 15 and just coming into my own with my confidence, as you can tell by the double denim and the pose. The photo would have been taken at a party at my parents’ house in Bournemouth. When I wasn’t filling up guests’ drinks, I’d be playing some songs – it looks like I’m playing B flat major, so I suspect at this very moment it was Hey Jude.

Leeds Grand theatre
Patrick Nolan’s thoughtful staging for Opera North shifts Pushkin’s story forward to explore the transition from Soviet state to elitist excess

For an opera rooted in 19th-century Russian romanticism it’s surprising how effortlessly Eugene Onegin can be brought up to date. Patrick Nolan’s thoughtful staging for Opera North, a co-production with Irish National Opera and his own Opera Queensland, manages to capture the aching melancholy of Pushkin’s original while reflecting on the equally gloomy transition from the Brezhnev-era Soviet state to the reckless excess of the pre-Putin oligarchy.

For Tatyana and Onegin, Tchaikovsky’s opera is a case of the road not taken, subtly reflected in the gently elasticated timeframe adopted here. In Act I, Leslie Travers’ crumbling civic gymnasium is commandeered to rehearse a pageant in praise of Soviet agricultural policy. When Madame Larina and the housekeeper Filipyevna chatter on about times past, Lenin-emblazoned flags remind us they would have grown up in the shadow of Stalin. As the gaudy tracksuits and 80s bling (costume designer Elizabeth Gadsby having a field day) of Act II give way to formal evening wear and diamonds in the final act, it feels as though an entire way of life has been swept away, and with it any chance to correct the mistakes of the past.

David Önaç uses insurance documents for work funded by Lloyd’s of London after research uncovered its slavery links

A centuries-old insurance document detailing the trafficking of enslaved Africans began with the words: “In the name of God, Amen.”

For Dr Errol Francis, the artistic director and chief executive of the arts and heritage charity Culture&, the contradiction was striking: an invocation of God in a document that treated human beings as cargo.