first we hear a pick up to the downbeat played by low strings and brass. the percussion gives a big cymbal crash on the downbeat as the fellowship race out of dwarrowdelf. the fellowship theme is in 6. in other words the rhythm is one two three four five six one two three four five six.
at :09 the high strings enter and slowly climb up the scale. this climb upwards helps give the feel of tension as the orcs chase the fellowship through the chamber of mazarbul. this tension makes us wonder if they will make it in time.
starting at :18 the rhythmic pattern changes to 5. one two three four five one two three four five, which is the rhythmic pattern for the uruk-hai theme. there are many layers of activity here. the orchestra is no longer working as a unit since the strings, horns and percussion are all playing something different giving a sense of chaos as the orcs get closer and closer. this is no longer the tuneful theme of the fellowship but the music of the enemy which tells us that the enemy is winning the race. the strings play short and fast notes traveling up and down the scale which gives a sense of movement as they race through the chamber.
at :45 the low strings and percussion start climbing up and up raising the tension higher and higher on beats 1 and 4 as the fellowship is surrounded until...
1:02 the orchestra stops the movement to hold a very dissonant chord. dissonance basically means that there is at least one note that is not in the scale and adds some tension. in other words, if you are in the key of c, then the scale that your piece is based on is as follows: c,d,e,f,g,a and b. there are no sharps or flats (the black keys on the piano) in the key of c. to have a dissonant chord you would add, let's say, an f sharp or a b flat, anything that is not in the original scale. the number of these notes called, "non-harmonic tones" and how close they are (half step or whole step) to the notes that are currently being played will determine the level of dissonance. here, the dissonance is very strong so there are many non-harmonic tones. howard shore also add to the tension by making the chord do a large crescendo. in other words, it gets louder!
at 1:05 the chord all of a sudden stops and only the low strings hold on as a drone as the balrog growls in the distance. men begin to sing and speak a chant, which seems very barbaric. this is the first time that we hear speaking in the soundtrack which gives the feeling of something new and terrible. there is also not a feeling motion with the absence of a strong beat.
at 1:24 there is a suspenseful chord as the fellowship is told to run by gandalf which leads to...
1:26 where the beat pattern changes to 4: one two three four one two three four. this strong beat by the percussion gives a strong sense of movement again as they run from the balrog. the horns are in the foreground while the strings play in a fast tempo. the music in this section is always building and going up the scale, which heightens the tension.
at 1:43 there is a sforzando, which means that you attack the note (play it loud) then back off immediately to piano (very soft) and then crescendo (get louder). this is done over and over by the brass. this is where boromir almost falls over the cliff followed by the hobbits. a sforzando is the perfect tool to use for a surprise.
at 1:49 the beat pattern changes from one two three four, as heard earlier, to one two three four and then varies where the strong beat is giving it a sense of disorder.
starting at 1:57 all beats have equal emphasis with the addition of the voices speaking the chant. this gives the feeling of the balrog getting closer. the horns continue to do sforzandos for tension.
at 2:08 one set of horns play up a scale while the other set of horns play a note, go up a step and then back down. these two play off each other like a call and response. then they play up a scale to increase the tension.
at 2:38 the horns play a fifth then go down a half step to the raised fourth. yes, for those of you who know what this is, it's the devil's interval. in medieval times the raised fourth was banned by the church because of the dissonance that it created. to hear what a raised fourth is, think of the song maria from west side story. ma- is the starting note, -ri- is on the raised fourth and –a is on the fifth. considering that we are talking about a demon of the ancient world, i think using the devil's interval is fitting.
at 2:47 the horns ascend the scale again and gradually get louder as the fellowship continue to jump over the gap in the stairs.
3:01 the rock falls breaking through the stairs and makes the part that aragorn and frodo are on unstable. here the voices re-enter singing their chant adding to many forces that are going against the fellowship.
the horns enter at 3:24 moving up the scale and increase the volume. also, the low instruments are not as prominent which gives the feeling of unstability – just like the unstability of the stairs.
at 3:35 one lone horn is added to the already large chord. the note it plays is not in the scale and it adds so much dissonance it's almost painful to hear. this is where the aragorn and frodo start to fall toward the others and...
at 3:37 they are caught by their friends and saved. here the fellowship theme (which is in 6) returns to let us know that they are safe.
but not really because the chanting starts up again at 3:54 in four with the strong beat on one. one two three four one two three four.
at 4:05 horns enter one by one using a sforzando approach to add to the already very dissonant chord and then they all do a big crescendo while gandalf battles the balrog until...
4:16 there is almost silence except for a low note that is held. this gives the sensation of being suspended in time while the balrog falls. it also tells you that even though the dissonant chord stopped, something is not quite right.
when the balrog catches gandalf with his whip, the percussion suddenly enters with a strong and rather loud beat pattern accompanied by the low instruments at 4:22. combining the two gives us the sensation of gandalf being doomed.
at 4:37 as gandalf lets go the low strings hold on to give us the sensation of being suspended in time again.
at 4:41 the choir enters with the low strings and sings completely tonal. in other words, all the notes are a part of the scale, like canon in d, and is a complete contrast to what we have heard in almost the entire track. this pure tonality is quite a shock to the ears after hearing such dissonance before. it almost makes what you are seeing seem not so real. something that sounds so beautiful cannot be happening while gandalf falls off the bridge. the disbelief that the fellowship feels is communicated to us in this way. a similar scene is done in red dawn while samuel barber's adagio for strings is played.
the boy soprano enters at 4:58 in what can be described as a wailing. i have associated that voice with frodo since he sings frodo's theme in track #17. a boy's voice is perfect for this since it does not have any vibrato. the absence of vibrato makes the sound cold and the fact that he sings to the vowel e instead of ah makes it even more piercing. the expansive and tonal chords continue to move under the singer and with the movement create a variety of color with dissonance. when you cry, there are different levels of grief that you feel and the movements of the chords help you feel this.
the track ends at 5:44 with a deceptive cadence. in other words, it doesn't end how you expect it to. to be technical, in the key of c major, the last chord should be a c major chord. you ear expects this whether you've taken music theory or not, it's just how our ears have been trained. this ends in a chord that is unstable and is in minor giving the feeling of unresolution. how could it resolve when gandalf has fallen into shadow?