It seems the art of survival—or continual positive projection—in the world of pop music these days, depends very much on change. If artists fail to recreate their image—chameleon(变色龙)-like, over and over again—they risk facing accusations of dullness; that they are not fashionable. This phenomenon is especially prevalent(普遍的) in the female ranks. It is not sufficient for an artist to be beautiful and y. These characteristics too must be changed often, and remodelled to avoid being bogged down(陷入困境) by a stereotype(老一套). Two examples of the rock "n" roll art of move and change are Cher and Madonna, the latter a brilliant illustration of the trend. Her latest disc, "Something to Remember", displays how she has so effectively been able to stay at the top without diminishing credibility in her particular field. (For these purposes, we will forget her unworthy flirtation with , that horrible book and her swear-word-ridden, cigar-chewing appearance on the David Letterman Show. ) This collection demonstrates how she has moderate her image at relevant times to give contrast and definition to her career. But it offers more than simply a study in rock fashion history. There is also a solid collection of quality music. It opens with the newish "I Want You with Massive Attack", a faintly morose and teary plea and quickly moves back in time to her earlier moments: "Crazy for You", "This Used To Be My Playground" and "You’’ll See". There is also a nice version of "Love Don’’t Live Here Anymore". So this is more than an exploitative offering. However, Cher’’s latest package, ’’It’’s a Man’’s World’’, cannot be reviewed proudly. In her past — the most memorable moment for this reviewer being her visit to a US warship amid cheering sailors for "If I Could Turn Back Time" — she has competed admirably. And she has demonstrated the classic features of the change syndrome(综合症). But this is a tired and dull Cher, Perhaps attempting to moderate her y and boy-crazy image in this session but failing. It can be inferred from paragraph 1 that in order to survive in the world of pop music, artists need to___________.