"The elder Mr. Rust, according to family oral tradition, declined a friend's suggestion that he name Victor's twin sister Decca. Often described as the father of contemporary discography, Mr. Rust embarked in the 1940s on a rigorous, deeply personal project that continued long afterward as he haunted archives and hunted down artists to reconstitute long-vanished recording sessions on paper. For decades, Jazz Records — known to jazz mavens simply as "J.R." — has been the de facto standard reference work in the field, furnishing meticulous information on session dates, personnel and much else for tens of thousands of recordings."