"Good Day Sunshine," as its title portends, radiates optimism and good vibes, even by the high standards the Beatles themselves set in those categories throughout their career. How many days like that in "Good Day Sunshine" do most people experience in their everyday lives? Well, they're not everyday occurrences, if people are honest with themselves. But on those occasions when they do arrive -- one of the first fine days of spring, just after you've fallen in love or started a vacation -- "Good Day Sunshine" is an appropriate soundtrack. Principal composer Paul McCartney was to agree that the good-time mid-'60s hits of the Lovin' Spoonful, such as "Daydream," were an influence upon "Good Day Sunshine," although "Good Day Sunshine" isn't as folk-rock-based as the Lovin' Spoonful's records were. The track's corn-eared hook is its frequent chorus, when the Beatles come together for some of their most uplifting harmonies. Its verses could have come from an old vaudeville song, sounding not just good-timey but old-timey, although the line about the sun burning the narrator's feet as they touch the ground is striking. The old-timey vaudevillian feel is heightened by the honky tonk piano solo (played by George Martin), a passage which might be too upbeat and sentimental for post-punkers, but ensured that popular music listeners of all ages heard what the Beatles had to say. In the final chorus, McCartney adds a nice touch by slightly modifying and bending the melody for straining emphasis. But the nicest touch of all is the unexpected fadeout, in which the harmonized chorus suddenly enters a higher key and round-like harmonies, as if the good vibes projected by the tune will not end when the record does, but echo around the skies indefinitely.