<prompt> Translate the following text to EnglishMtu lazima kugeuka kwa orodha ya habari, na mgeni curator Richard Kendall, kujifunza kitu cha hii tukio unpleasant katika maisha ya Degas, somo zaidi kwamba avant-garde sanaa na siasa retrograde mara nyingi kuishi pamoja.  <response>: One must turn to the informative catalog, by guest curator Richard Kendall, to learn something of this unsavory episode in Degas life, a further lesson that avant-garde art and retrograde politics often coexist. 