Revolver is The Beatles at their peak of creativity. Surprising shifts in mood prevail on this album —ranging from the bright positivity of "Good Day Sunshine" to the paranoia of "She Said She Said." The balance of pure harmony ("Here, There and Everywhere") with jangling electric guitar ("And Your Bird Can Sing"), orchestral character portraits ("Eleanor Rigby") and brassy soul ("Got to Get You Into My Life") is seamless. Revolver is also one of the first psychedelic albums—with backwards guitar, sitar, sound effects, and complex lyrics throughout—culminating in the mystical finale of "Tomorrow Never Knows." Filled with revolutionary studio advances and perfect song craft, the end result is a towering artistic achievement.