Jónsi Birgisson and Alex Somers, Courtesy: Lilja Birgisdottir. LOS ANGELES — If the new analogue remaster of Riceboy Sleeps caught some ears, the long-awaited orchestral performance of the record rattled the soul. Ten years after Sigur Rós frontman Jónsi Birgisson and film composer Alex Somers released their immaculate ambient project, the…