Which pop duo had a 1989 hit with "Blame It on the Rain"?

Which composer's opera "The Marriage of Figaro" premiered in Vienna on May 1, 1786? Florenz Ziegfeld produced which 1927 musical, whose song "Can't Help Lovin' Dat Man" includes the line "Fish gotta swim… In the 1969 Broadway musical "1776", the song "He Plays the Violin" is sung about which Founding Father? In 1927 Al Jolson sang which Irving Berlin song in "The Jazz Singer", a tune that became a hit for Willie Nelson about… Which Motown group had a 1978 No. 1 hit with the ballad "Three Times a Lady"? Which 1847 Giuseppe Verdi opera, based on Shakespeare, features choruses of singing witches? Which "Bonanza" star topped the charts in 1964 with the spoken-word western ballad "Ringo"? Shalamar's song "Dancing in the Sheets" appeared on the soundtrack of which 1984 Kevin Bacon film?