I never heard the sxxx from this book that is supposed to pass for "music(??)". However, from what I have heard, the singing is pretty lame and sounds like dying cats. They do that on purpose--when they sing on the CD, they use the correct notes. However, the song book has notes that, when sung according to it, will sound terrible. This is so the witlesses are deprived of anything that resembles pride of accomplishment and they can beat down on them for lousy singing.
There are now only 135 songs, instead of 225. Supposedly they are shorter--many had a verse cut out. And yes, the lyrics and the "music(??)" (if you can call that atrocity from a drunk playing the piano "music") have been tampered with. And not only do they sound like dying cats and cult chants, many of the lyrics are now blatantly blasphemous. Where before you had two songs (27 and 61) singing as Jehovah in the first person without quotation marks, now you have direct idolatry of the Filthful and Disgraceful Slavebugger. I decided it wasn't worth wasting my electricity trying to find out just how horrible they sound for myself.
