Producers and investors may be attracted to the odds of financial success promised by the idea of musicalizing a successful movie, but it has to be a bit more daunting to the writers who have to compete with the memory of the film they're adapting. It's impossible for anyone familiar with the source material to avoid comparisons, and hard for a viewer to judge the new piece as a work of its own. Maybe some time simply must pass and the new piece has to develop its own life and following. This first national tour (and second company) of The Color Purple may be an important step in viewing the show on its own merits.