I hold emotional gravity to be one of the most important qualities in music. This is why the crushing sounds of sludge metal have captured my interest for the past few months. Sludge is a subset of doom metal that specializes in incredibly heavy (in the low-tuned sense) instrumentals. It can be likened to post-rock for its ability to take the listener to another world, and in fact, it has been called “post-metal” in some instances. All I can tell you is that it is some of the greatest music I have ever heard.I could go on about all the sludge bands I’ve been listening to, and I will provide a short list at the end, but Isis are my favorite by far, so I will focus on them. I did not know what to expect out of sludge metal before I discovered Isis on last.fm, but their top track, So Did We, blew me away. It has a number of amazing qualities: the musicianship is spot-on; the vocals do not take away from the song, and actually serve more as an instrument in the song; it is a dynamic song, so it does not get repetitive at any point. Allow me to state why these things are important, so as to further insult the genres of music that I feel fail in these departments. It’s always a good thing to hear a song where the instruments just work. There is a bass guitar in this song – it isn’t lost under the wankery of an overly-excited lead guitarist. The keyboard is there, the drums are there, the guitars are there, the vocals are there. Nothing is missing or forgotten. It just works, and it’s because they put some thought into this song as opposed to letting an algorithm generate it. What I particularly like about the vocals is that they are riding the flow of the song. It reminds me of something floating on water – the vocals don’t disturb the music, and they are more a complement to it than anything else. I am rarely a fan of adding vocals to an instrumental song, but it works here because of timing, and the singing style of the vocalist. Timing is important because it means he is not singing through the whole song – there are moments where you can be washed away by the music, and moments where he rescues you. As for his singing style, the significance is simply that he does not do anything distracting. He doesn’t take the spotlight away from the song by being flashy or doing the vocal equivalent of a guitar solo. His voice is another instrument, and I commend that. The last and most important thing about the song is that is dynamic. It has heavy moments and it has soft moments. It has slow moments and fast moments (as fast as sludge will allow, of course). You don’t get a sense of listening to the same thing over and over for the duration of the song, and as such, it can safely go past the precious three-minute-thirty-second mark of radio music and not bother anyone. It is not a boring song. You can actually listen to it without needing to distract yourself with other things, if you so desire. You’ll find most good music is dynamic in this way, and all bad music is not. So Did We is just one song off Isis’ Panopticon album, and I would recommend that album as well as their entire discography. I’m a big fan of Oceanic, off that list. If you’re looking for that genre for metal that does what post-rock does for hard rock/alternative, I suggest sludge. Some of the other sludge bands I’ve been checking out are (in order from most similar to Isis to least similar): Rosetta, Pelican, Ufomammut, Electric Wizard, The Ocean. They are all great bands. Enjoy the new degree of arrogance that metal-listeners have been afforded by this genre’s existence.