"A Day in the Life" exists in the space between unawareness and disenchantment — the space that the times now moved in — and it closes with the most famous moment in 1960s music: a single chord played by Lennon, McCartney, Ringo Starr, [George] Martin and Mal Evans across several pianos at once, reverberating on and on, like a possibility without resolution. It was the abyss at the end of the dream, the void that the dream had to somehow surmount. As that eventful chord lingered and then decayed, it bound up an entire culture in its mysteries, its implications, its sense of providence found and lost. In some ways, it was the most stirring moment that the culture would ever share, and the last gesture of genuine unity that we would ever hear from the Beatles."
–Mikal Gilmore, Rolling Stone magazine,
The Beatles: The Ultimate Album-By-Album Guide (2011)