Madonna (entertainer)
Madonna entered mainstream films in February 1985, beginning with a brief appearance as a club singer in Vision Quest, a romantic drama film. Its soundtrack contained two new singles, her U.S. number-one single, "Crazy for You" and "Gambler". She also appeared in the comedy Desperately Seeking Susan in March 1985, a film which introduced the song "Into the Groove", her first number one single in the United Kingdom. Although Madonna was not the lead actress for the film, her profile was such that the movie widely became considered (and marketed) as a Madonna vehicle. The New York Times film critic Vincent Canby named it one of the ten best films of 1985.

Q: What song did the comedy Desperately Seeking Susan promote?
"Into the Groove"