On today’s date in 1923, the Finnish composer Jean Sibelius conducted the premiere performance of his Symphony No. 6 in Helsinki. He had begun work on it some five years earlier, and at that time described his vision for the symphony as follows: “The Sixth Symphony is wild and passionate in character. Gloomy with pastoral contrasts. Probably in four movements with a finale, which will build to a gloomy, wild romp of the orchestra in which the main theme disappears.” Well, that may have been the original idea, but the final product turned out quite different, and the late musicologist Michael Steinberg offered a more spot-on description: “The Sibelius Sixth is transparent, pastoral, lyrical, and notably even-tempered—a sanctuary fashioned out of music.” In the pecking order of popularity, the Second and Fifth of Sibelius’s seven symphonies rank at the top, with the Sixth probably the least-often heard in concert. But the always perceptive Mr. Steinberg, wrote: “To this day the Sixth remains the least known (or understood) of the seven symphonies, and yet for those who make its full acquaintance, the Sixth may become the most cherished of them all.”