She started her career as an inoffensive pop singer who sang of the benefits of getting "mellow" ("Have You Never Been Mellow"). Her transformation into a brazen aerobics sex-throb with "Physical" is as radical as what happens to her character, Sandra Dee, in the movie Grease. Three cuts from which ("Hopelessly Devoted to You," "You're the One That I Want," and "Summer Nights") are featured here. Add a few other hits, "A Little More Love" and "Magic" and you've got a full spectrum view of what she can do. From syrupy ballad queen to workout addict, she got it on the radio. --Rob O'Connor