Drums in the Deep
Having done a Google search on this, I see this topic has been discussed previously. However, I'd like to re-address it.
The "Drums in the deep" that the Fellowship hears in FotR, The Bridge of Khazad-Dûm - are generally accepted to be just that - drums. Orcish war drums to be precise. I disagree. I don't think they're drums at all but rather the Balrog's voice. I don't have the time to make this post the quality I would like it to be, so I'll just state some quick points and let the community take it from there.
First and foremost - when we first hear the "drums" they are described as "a rolling Boom that seemed to come from the depths far below, and to tremble in the stone at their feet." Now no doubt war drums can be loud, but what are these drums that are so large that from "far below" are able to penetrate Eru knows how many feet of solid rock and cause the floor to tremble. They would have to be utterly massive. "...as if huge hands were turning the very caverns of Moria into a vast drum". Keep that in mind. Interesting - as if the caverns themselves are a drum, not as if there's a massive drum in the caverns.
Then "Doom, Doom came the drum beats and the walls shook....amid the clamour a deep voice was raised in command. Doom, boom, Doom when the drums in the deep". The deep voice is obviously the Balrog. The Drums are still "in the deep". Shaking the walls. Or is it simply the tonal depth of the Balrog's calls, penetrating walls and stone, sounding like drums in the deep when in reality it's not far at all? In any case, the drums and voice now seem to be connected, as you'll hear soon. Why would these drums somewhere "in the deep" be linked to what the Balrog or even the orcs are doing however many floors away?
Later: "Doom, Doom went the drums in the deep. The great voice rolled out again".
Now I'll paraphrase this next bit. Basically, Gandálf is holding the door with a spell. The Drums are beating occasionally, the walls shake. The Balrog perceives Gandálf and casts a counter spell on the door. At this point the drums beat wildly. The door, along with the wall and chamber itself collapses, and the drums stop completely for a time. Here's the critical part, to me. Again, these "drums in the deep" are mirroring everything the Balrog does. Beating occasionally while the Balrog is entering the room and investigating the door. Beating wildly while he is attempting to counter spell the door open, ceasing when the room collapses. Why? How would the unknown drummer "in the deep" even know what the Balrog is doing?
The drum beats start back up again, muffled and distant but following. If it was an orc drummer, who now seems to not be in the deep but to have been in the room with the Balrog, how would it have not gotten crushed and killed when the entire Chamber of Mazarbul collapsed? That's something a Balrog could survive. But not an orc. It could be the cave troll beating the drum and yet nowhere is there connection to the troll and the drum. No drums when the troll is approaching or trying to enter the room.
Then "Doom, Doom rolled the drum beats, growing louder and louder.... Legolas turned and ... gave a cry of dismay. Something was coming up behind them...like a great shadow".
Finally after Gandálf and the Balrog have fallen: "faint and far beneath the earth rolled the slow drum beats".
Again, I don't have time to make this post the quality i'd like. But I assert that the "drums" are actually the Balrog, a kind of call. But the story is told from the Hobbits perspective. We're talking about a fallen angel demon that would be very hard for mortals to comprehend. I think "drums" was chosen to describe the sound because Tolkien didn't want to break character by saying "it sounded like a gigantic demon monster calling out" because the hobbits couldn't even comprehend that such a thing existed.
I think if it had indeed been drums, the source would have eventually been revealed, since the "drummer" seems to not be in the deeps at all, but following the fellowship. And always somewhere near the Balrog.
That's all for now. If I have time tonight I'll clean this post up. What's everyone's thoughts?