The Man from Planet X (1951)
The Man from Planet X is a 1951 American science fiction film starring Robert Clarke, Margaret Field and William Schallert.
A spaceship from a previously unknown planet lands in the Scottish moors, bringing an alien creature to earth near the observatory of Professor Elliot just days before the planet will pass closest to the earth. When the professor and his friend, American reporter John Lawrence, discover the creature, they help it when it is in distress and try to communicate with it, but fail. Interestingly, it is later revealed that the alien can only communicate using modulated musical sounds, a concept used three decades later in Close Encounters of the Third Kind.
Here is the official 1951 trailer …