Few 87-year-olds would have the stamina to conduct over 100 minutes of Mahler. Bernard Haitink, though, has always kept a steady, unruffled hand on the interpretative tiller, and if his way with the longest of all the symphonies, the Third, hasn't changed that much since his first recording made half a century ago with his Concertgebouw Orchestra, there's still reassurance in the sheer beauty of the music-making.