You bring up an interesting question about whether Thrice's music should qualify as "Christian" or not. I decided to included them in the CProgPositivity playlist because their lyricist (Dustin Kensrue) is a Christian, his lyrics often deal with important themes from a uniquely Christian perspective, and because I'm not aware of any instances in which his lyrics have been incompatible with Christianity. Not every member of their band is a believer, but on many "Christian" songs on "Christian" labels, there is work by engineers, producers, or session musicians who may not be believers too.
Descriptions like "heavy" are challenging. They beg the question "heavier than what"? How "heavy" one perceives a band to be often depends upon the listener's "frame of reference". Most of the listeners to CProgPositivity consider Thrice to sound "heavy" when compared to the rest of the music they normally listen to. But I do agree that there are far "heavier" bands out there and from your point of view, they may not seem to very heavy al all to you.
There are emo influences but also some post-hardcore and nu-metal sounds mixed in. I think perhaps they are less "heavy" now than when they first started out even though CD Universe's review claims they have "maintained every iota of their heaviness..." (See
http://www.cduniverse.com/search/xx/.../a/Vheissu.htm)
There were so many bands in my listing, I just tried to quickly provide some type of classification so that interested music fans might at least get a general idea where to start. The links found at this website will provide much greater detail about the bands.
http://sites.google.com/site/cprogrock/directory
Thanks for your feedback!
Bookmarks