This year, on the 50th anniversary of the composer's death, Andris Nelsons and the BSO conclude their award-winning ten-year Shostakovich project. The superb acoustics of Boston's Symphony Hall inspired Yo-Yo Ma's recording of Shostakovich's two cello concertos. The imaginative First was written for another friend, Mstislav Rostropovich, a famously challenging piece that marked an early milestone in Ma's own career. The far more introspective Second was the composer's birthday present for his 60th birthday. Performing the latter work to the Symphony Hall audience, Ma said: "This piece is as relevant today as it was then. I believe Shostakovich's artistic truth was to give a voice to the voiceless."