Be careful when presupposing greater knowledge over someone else - you will almost always fall down. First of all, METROPOLIS was German, not made in Hollywood, but even if it were, it wouldn't matter because it was a silent picture whereas KING KONG was a sound (talking) one. Music over a silent film was almost always a necessity - every theatre had at least a piano, and a number of silent films were released with scores added - and in the case of DON JUAN (1926) was released with great fanfare as the first film with an audio soundtrack - composed alongside the action - and sound effects. Others include MGM's THE VIKING (1928). It's true you have to differentiate between scores written for silent and those written for sound. Any film music for a sound film (not a musical) was almost always written by Max Steiner (excepting, of course, main or end title music or diegetic examples like bands, orchestras, radios or record players.

The other important point is this issue of composing along to 'beats' of the action. In fact, Steiner was instrumental in the development of the 'click track,' which was used for exactly that purpose, aligning the music to beats, action, emotion and - the big addition that was not a problem for METROPOLIS - dialogue!

While there were one or two Hollywood films appearing with music in the background - Newman's STREET SCENE (1931) springs to mind - Steiner's KING KONG is rightly heralded as the first major score for a SOUND FILM so intricately composed that it almost appears at one with the action. Music for silent film is another issue altogether.

That's a potted history of sound vs silent film scores, because doing a little homework before posting one's suppositions can be useful... x

the 1927 score for Fritz Lang's METROPOLIS was composed at the time of filming, and was very specifically composed and charted to align with the scenes, beats and events of the film itself.

Granted on might have to be an aficionado of Fritz Lang or of METROPOLIS to be aware of this, but doing a little homework before posting one's suppositions can be useful...

As previously posted by another user, Max Steiner's "King Kong" score is in fact THE ORIGINAL "Original Motion Picture Score". Max Steiner had a huge role in creating/scoring music for film, and his work has influenced & inspired many others to pick up the mantle and compose for film. The great Sir John Williams of "Star Wars"/"Close Encounters"/"Jaws"/"E.T. The Extraterrestrial" scores has often accredited Max Steiner's work as a major influence for his own work.
If you've ever watched the original "King Kong", listening to this amazingly orchestrated beautiful score with your eyes closed will induce visions of the scenes the music was composed.
Truly one of the greatest motion picture scores of all times.

Many people do not realize that this score is the first written just for a movie, that followed the beats of the film with special music for only that scene that was showing at that moment. Before King Kong, films had generic music that sometimes didn't match what you were watching. A case in point was two years earlier with the release of Dracula which started during the titles with Tchaikovsky's Swan Lake theme. It simply was not appropriate. This was the start.