CHAINED MELODIES; Angel and Marty Tish, a husband and wife singing duo named "America's Sweethearts," go to Sing-Sing to perform for the prisoners while trying to mend their long-term marital problems. THE TEST; Sara and Greg don't know what to tell Max about the possibility of Sara being pregnant while taking a home pregnancy test. THE PAGANS; Bart, Lisa and Maggie dress as pagans to escape going to church one Sunday with Homer. (thetvdb.com)