You'd think they could've properly mic'd the acoustic guitar for the solo, but this was a time when perfection didn't mean perfection. We've gotten very fundamentally literal since those times.

No matter, this is the perfect Led Zeppelin ballad, so melodically inspired. I almost don't even notice its great creativity anymore because I've heard it so many times, but you really have to wonder at all the distinctly different sections in this song, starting with the full band instrumental opening to the verse vocals backed only by church organ, to the full-scale choruses, to the guitar solo played within a reprise of the instrumental opening, to the fade out/in organ solo ending.

Robert Plant got few chances to sing pure without needing to seem possessed by blues demons. He really could fill the church.