"Elder Misanthropy" from the 1st CD Unhallowed is prob the best BDM song, but the newest CD is all very good. I'm old school death metal like Deicide, Obituary, ect. but I have to say BDM is fucking brutal, and not just because i'm from the same area. If u like them check out another local Detroit band called Battlecross, drummer is phenomenal. There gonna be the next D-town metal band to break it.
the secondary vocals you are hearing is the rhythm guitarist. he has always helped a bit on and off with the vocals. they sound nearly identical live to what's on their cds, and to get the echoing sound, the guitarist helps. as well he also writes the music and many of the lyrics. About the pitch i guess thats because the singer, Trevor, just has a good vocal range.