I think screamo music it's self can glorify God if the message of the song is aimed at revealing truth that our God has set before us. If the song is displaying emotions of pain, hurt, and suffering, the musician is simply using his talent to the best of his ability to explain to others the suffering he is going through. For a musician, expressing those feeling is very uplifting and even though others might not be uplifted I know some are very uplifted by it because everyone wants to know that there is someone else in the world who feels their pain and these songs can provide that connection between the musician's pain and the listener's pain. Also, shouldn't we glorify God in EVERYTHING we do? Regardless of the fact that the song may not be telling the greatness of God, it still can be glorifying him by sharing the feeling of pain we suffer for our lord. Timothy says "join with me in suffering for the gospel and for our Lord". This music can be very real to life when put in perspective with the trials we go through for our faith. Going through those trials can definatly cause the feelings that musicians convey in screamo