The Beatles- I Need You. 1965. George Harrison composer. George Martin engineer. It's important because it's the first use of wah wah pedal by a major artist. It also introduces the rest of the composition beautifully. This intro is 4 notes.
This Boy ~The Morecambe and wise show 1963 ... John Lennon wrote this song. One of his early compositions, it is seemingly simple, but very clever. The song contains only a few notes, but the space between the notes is filled by the arrangements. It's the same technique you hear in Liszt's "Liebestraum," the piano piece in Schumann's Davidsbündlertänze and in Beethoven's "Moonlight Sonata."