It’s been nearly five years since the American composer Robert Ashley passed at age 83. Noted if underrated as a groundbreaker in the field of 20th century opera, he’s just as appropriately described as a leader in the modern avant-garde. But where many of his contemporaries were minimal, Ashley was labyrinthine. This may lead a novice to conclude that his work was formally rigorous or even downright severe, but in fact his mature work can be quite accessible while possessing depth that’s effectively inexhaustible. Private Parts is a crucial serving of the man’s brilliance, and on February 1 it’s getting reissued on vinyl by the folks who put it out way back in 1978, the aptly named Lovely Music, Ltd.