TV's Frank wrote:
From talking with the guys who produced this set, I learned that it simply was not possible prior to recently, for many different reasons. These obstacles prevented any label from releasing all the scores from the show on disc, but once this was finally resolved recently then work could begin in earnest.
Are we talking mainly licensing obstacles, technical ones, logistical ones, or all of the above? Were there some scores that weren't available in sufficient quality until now? Were the rights spread out among too many labels and only recently reverted? Were there issues with the approval of some of the composers or their estates?