There are some who might say that "Kashmir" is the best song on Led Zeppelin's 1975 album Physical Graffiti. Bless them. Clearly they have never heard "In the Light."

The drone sections create emotional stakes an idiosyncratic potboiler like "Kashmir" could never hope to attain. Let's just start there.

The guitar riffing in this song is elite order, both the descending chorus line and the marching verse pattern. It's not just the notes on the page; it has to do with the nearly-but-not-quite clean tone of the guitars too. Led Zeppelin sometimes found ways to achieve heavy guitar tone with resonance rather than gain. The verse vocal is brazenly collected and well-plotted. The drums are so creative, avoiding the beat in the choruses with bass drum flutters and snare/cymbal accents, then laying down the most businesslike, straightforward pattern for the verses.

The breakdown puts the spotlight on John Paul Jones' keyboard, using a great voice. The first time this part is played, there is one simple guitar melody accompanying. For the second, final return of this section, the guitars multiply into excellent, intersecting harmonies, fading out amidst their architecture.

Such originality, such heft, such light.