Margaret Mikulska >I don't know how "The Age of Gold" and its suite became op. 22 and op. >22a (there might have been another work with op. 23 before the suite was >compiled), but generally, when an "a" or "bis" is appended to an opus >number, there is no connection between the two - just as in the Kochel >catalogue (no connection either). Shostakovich seems an exception here. Comming to DDS its quite simple with the lettering of sub-opuses, Shostakovich made a rudimental Opus list himself, mostly of the major works, that did not make room for filling in blanks, then when suites and unnumered works has been found or put togehther, not least post 1975, the have been given letter + an Opus number so that the work would come in chronological order. I guess (the best I can do), that it was choosen rather than creating a completely new system ala Kochel, which I belive would have made things very difficult when You already have and established Opus canon. Comming to the 'Age of Gold' I find it Quite logical that the Ballet (the original work) gets a straigt Opus number and that a suite drawn from it gets a sub-opus, not? peter lundin, gothenburg.se - Counting the days: DDS 100 (1906-2006)