Which song, released in 1965, is considered Bob Dylan's magnum opus and a cornerstone of the folk-rock genre?

Bob Dylan's magnum opus, and one of the most celebrated songs in popular music history, is 'Like a Rolling Stone'. Released in 1965 as a single from his album 'Highway 61 Revisited', the song represented a departure from Dylan's earlier, acoustic folk material and marked a turning point in the genre, which became known as folk-rock.

'Like a Rolling Stone' is considered a masterpiece for its innovative lyrics, complex sound, and its powerful message about alienation and social mobility. It topped charts in both the United States and the United Kingdom, and its popularity helped to establish Dylan as a major figure in the music industry.

The song's impact on popular music is immeasurable, influencing countless musicians and artists in the decades since its release. It has been covered by numerous artists and featured in films and television shows. In 2011, 'Rolling Stone' magazine named it the greatest song of all time.