Layla (Derek and the Dominos)

One of rock's great structural surprises: the piano-and-slide opening section, elegiac and almost classical in its emotional weight, exists in an entirely different register from the hard, grinding electric section that follows — and the fact that they share a song, that one bleeds into the other, is part of what makes the whole thing feel so emotionally volatile. Duane Allman's slide guitar work in the opening carries an aching, vocal quality, each note bending as if trying to reach something just out of range. Clapton's voice is raw and exposed in a way his playing sometimes obscures — the desperation in the lyric is real, drawn from an actual unrequited love that was consuming him, and it comes through without performance. When the song shifts into its rock mode the grief transforms into something more combative, almost angry. The outro stretches into an extended instrumental that gradually loses urgency and dissolves into something peaceful, as if exhaustion finally overtakes desire. Derek and the Dominos made this at a moment of real personal and creative crisis, and that instability lives inside the recording. It's late-night music, 2am music, the kind of song that finds you when your feelings are larger than your capacity to manage them — and rather than offering resolution, it simply confirms that someone else has been here too.