So, what should he play?
An ensemble of over 150 string players gathered in London's Trafalgar Square to pay tribute to the victims of the Charlie Hebdo massacre in Paris.
The event was organised by the Allegri Quartet who reached out to musicians, asking them to assemble by St Martin in the Fields church to play Samuel Barber's Adagio for Strings.
The initial plan was to play inside the church itself, but reports on Twitter suggest that the venue pulled out due to security fears. The ensemble instead played just outside.
"Adagio for Charlie Hebdo" is organised by @AllegriQuartet . St Martin's-i-t-F, withdrew as venue at the last minute."Security fears". Shame.— KateMaltby (@KateMaltby) January 8, 2015
The ensemble, which appeared to feature members of the Sacconi Quartet among other professional players, met at around 9.45pm for a quick run-through, and then performed at 10.45pm, after holding a minute's silence and a brief introductory speech.
Watch the whole performance here:
(video via Alexander Barnes / www.appleandbiscuit.com)
A Facebook page to publicise the performance suggests that almost 2,000 people attended the event.
Cellist with the Allegri Quartet Vanessa Lucas-Smith told slippedisc: "We were united in cause; one of remembrance, of the shock and horror of the brutality of the Charlie Hebdo massacre, of sadness for the victims and their friends and family and of the determination to stand up for democracy and freedom of expression."
"Living in these times we need as many reminders as are possible that most people act with love, kindness to others and with generosity of spirit. "