(that's me trying to be witty)
The word "monolithic" gets tossed around a lot these days, as do "epic" and "awesome". The number of musical projects that I would describe as monolithic is tiny, among them are Neurosis and Earth. If you have even the slightest interest in drone/doom, you would have heard of Earth. Fun fact: Sunn O))) is so named because of 1. worship of the Sunn O))) equipment and 2. they thought it would be a cute little tribute to Earth (Sun and Earth...get it?). Earth's influence is without a doubt massive and their music amazing. Here are 2 awesome albums of theirs.
The first album is Pentastar: In the Style of Demons. It's sort of mind-boggling due to the facts that it has a predominantly stoner rock influence and that it was released after Earth had established themselves among the pioneers of drone/doom. That aside, this is a beautiful album. Incredibly soothing. On the other end of the see-saw we have...
Earth 2. This, ladies and gentlemen, is an abso-fucking-lutely huge album. Now, I know a lot of you can't stand drone or anything with even a lot of feedback in it (fuck you), but I believe everyone should listen to this album. This, my friends, is monolithic.