The theme song to the film , `` It Might Be You , '' which was sung by singer-songwriter Stephen Bishop , whose music was composed by Dave Grusin , and whose lyrics were written by Marilyn and Alan Bergman , was a Top 40 hit in the U.S. , and also hit 1 on the U.S. adult contemporary chart .
The theme song to the movie , `` It Might Be You '' , was a Top 40 hit in the U.S. , and also hit # 1 on the U.S. adult contemporary chart . Stephen Bishop sang the song and the music was by Dave Grusin / Marilyn and Alan Bergman .