Legend has it...
This is a two part connect wall puzzle. The sixteen movie and TV titles below can be arranged into groups of four that are related by a common theme. The four themes themselves have a common theme, which is the final answer.
Aladdin (1992) Beaches (1988) Breakfast at Tiffany's (1961) Ghost (1990) Gone with the Wind (1939) Iron Man (2008) Monk (2002) Phantom of the Opera (2004) Schindler's List (1993) Sesame Street (1969) Some Like It Hot (1959) Star Wars: The Force Awakens (2015) The Odd Couple (1970) The Sound of Music (1965) The Umbrella Academy (2019) Titanic (1997)
Note 1: The years are provided to disambiguate in cases where multiple versions of the title exist.
Note 2: You will definitely need to use the internet to solve this, although I hope the themes can be guessed with only minimal research.