Source: The Wall Street Journal Concerts to celebrate the most-performed classical-music composer alive By STUART ISACOFF You may not know the name, but you’ve heard his music. Estonian composer Arvo Pärt’s alluring, hypnotic “tintinnabuli” (“bell-like”) style has resonated with listeners world-wide—the database Bachtrack reports that Mr. Pärt is now the most performed living classical composer. The haunting music in the trailer for the film “Gravity”—a perfect complement to the image of astronauts adrift, its piano pattern suggesting a cosmic clock as floating violin tones and spacious pauses convey a sense of human frailty—is his 1978 work, “Spiegel Im Spiegel” (Mirror…