This is kind of an odd one I think. It starts off with a drum beat for probably two measures if two-four time and then the band comes in. The drums play a nice rock beat and the bass does some stagnant stuff. The lead guitar plays the recognizable low part, do-do-do-do (up octave)-do. The band plays for eight measures and then Robert Plant comes in with the scream/yell things, do-do(up)-ti-do(up). He does the scream thing twice, eight measures in all. The same chord is played for both the band and scream introduction parts. Then, in the seventh measure, the rhythm guitar and rest of the band comes in and the chord changes to V. The melody comes in, “Come-to-the-land-of-the-ice-and-snow” which is sol-sol-sol-sol-sol-do-sol-sol. The next twenty-four measures almost sound like one big long melodic phrase. The next eight measures build up. His vocals move up the scale and crescendo but lead back to the original guitar riff. What a surprise, the beginning of the song repeats! This time, after the build-up there is a new, fairly short, melodic theme. Plant does some spooky sounding oohs, sounding slightly ghostly, and then the song ends.
I have heard this song before, but I never really realized that it was Led Zeppelin. I am interested in looking at the lyrics more closely because it seems to talk about the strife of immigrants. The scream is a cool way to display their pain. The music is interesting because it sounds kind of minor and dark.