There are a few different manners by which a band will rape their own legacy. The most common is by simply remastering an album for re-release. Then there are times when they re-do parts of the recording, but not the entire thing. And, finally, there is the complete re-recording, whether of a song or two, or an entire album.
In the case of remasters, it's something that has been going on for quite some time. In many cases, it's hardly noticeable, and does nothing to severely alter the atmosphere of the original. Then there are bands like Megadeth, that want to “update” the albums so that they sound more contemporary. Some years ago, I found myself at the home of an acquaintance, looking for some tolerable music to listen to. I ran across the remastered version of Killing Is My Business.. and Business is Good! The different cover art was already enough of a turn-off, but suffering through the horridly altered music was another story. It was offensive, right from the beginning, yet some kind of morbid curiosity compelled me to continue. Not long ago, I learned that the other Megadeth albums also received this treatment, and sampled bits and pieces, for the sake of forming an opinion. The general feeling that I got was of having been aurally raped. One of my strongest reasons for disliking newer music is the sterile modern production that does nothing but suck the life right out of the music. Taking this mentality and robbing old albums of the aura that made them special is ridiculous. And this isn't merely limited to albums that I grew up on; i.e. this sentiment is not based on nostalgia, alone. The same goes for any Speed/Thrash album that I happen to dig up, all these years later. If any of those had such an empty and lifeless production job, I'd hate them as well. If the person in charge of remastering the album limits himself to making sure there are no imperfections (such as a drop in sound) then that is a different matter. In some cases, the clarity of the compact disc revealed imperfections from the source tape that weren't as easily noticed on vinyl or cassette, such as Anthrax's Fistful of Metal. If it was possible to go in and remove those imperfections without compromising the integrity of the album, that would be fully acceptable.
There are cases where an album needs to be remastered. Looking at some of the albums that came out of Hellspawn/Unisound, one can't help but feel pity for a few of those bands. In particular, Marduk was completely raped and had the impact of such works as Those of the Unlight and Opus Nocturne reduced to almost nothing. Years later, when they were remastered, it was for the better and only served to bring out the potential that was always there.
That brings up another interesting point. Perhaps this is what some artists feel they are doing. It could be that they were dissatisfied with the results and that the music did not live up to their original vision, whether it be due to errors in the production or the playing itself. However I see a strong difference between cleaning something up and trying to modernize it.
The next step is to actually re-record parts of the song, while retaining the rest. In some cases, someone will go in and re-do the bass lines or the vocals. Ozzy had the bass and drums re-recorded and replaced on his early albums, due to a royalty dispute with former bandmates. The result was more horrible filth that destroyed the feeling of the original albums though, being Ozzy releases, it wasn't nearly the same level of crime as the aforementioned Megadeth trickery. And speaking of Dave Mustaine, he is guilty of re-recording things as well. I don't have all the facts, but it seems that when it came time to remaster and reissue Rust In Peace, it was discovered that some of the original tapes were missing. This lead to the “natural conclusion” of re-recording some parts, and using alternate takes for others. This not only ruined the album, but completely killed it, dead. With the original being out of print, future generations will now have no choice but to accept this trash as the one and only version of this Thrash classic, without even knowing that they are listening to an inferior recording. My question is why they didn't just use an existing CD and make minimal changes (as I'm guessing one cannot do so much without having the separate tracks), but would still be better than altering the album. Of course, in my opinion, the album was fine as it was and didn't need to be tampered with, whatsoever. Then there was the more recent case of The Crown. I'm not terribly familiar with them, but I do remember reading that when their original vocalist returned to the band, they re-released the album that featured Tomas Lindberg, with his vocal tracks replaced.
Finally, we come to the issue of completely re-recording select songs, or even entire albums. In a sense, this is not as bad as the previous crime, since it is fully acknowledged as being a new recording rather than meddling with existing albums and trying to pass them off as the originals. What are the motives for re-recording music that has already been released on a proper studio album? In most cases, it is a matter of the artist not feeling that the material was presented as he intended for it to be.
Look at Burzum's “A Lost Forgotten Sad Spirit”, which was re-recorded a short time later for the Aske E.P. Varg was able to get the song just as he wished, and made this “correction” within a short time of the original release. In a situation such as this, it seems completely understandable. However, other times, it appears to be much more pointless. Take Black Funeral, for example. They released Vampyr – Throne of the Beast in 1996, and then re-recorded 85% of that material for Empire of Blood, in 1997. The arrangements were pretty much the same, with only the production and vocals being altered. Overall, this was rather useless, and a bit deceptive since the songs were all given new titles and no mention being made that they were the same as what appeared on the previous album. Still, it was within a relatively short amount of time and the argument could be made that the band members weren't pleased with the result of their 1996 effort, or simply chose to go in a slightly different direction afterward.
Another reason to re-record an old song is for the band to showcase new members, usually for an E.P. Hypocrisy did it, on Inferior Devotees, re-recording a song with Peter on vocals, as a way of introducing the fans to his vocal style and to show that he was competent enough to fill Masse's position. As with the previous examples, this was done a short time after the original, and seemed to serve a specific purpose. However, as much as it pains me to bring this up, Dissection proved that, sometimes, the past needs to be left alone.
When Jon Nödtveidt was released from prison and reformed Dissection, they re-recorded “Unhallowed”, for the Maha Kali E.P. While they succeeded in displaying the skill of the new lineup (which I am sure was the ultimate goal), the song failed to capture the magic of the original. As an obsessed fan, I came to enjoy this rendition as well, but even I would not try to claim that it matched the version found on Storm of the Light's Bane. Still, in the end, it was merely a bonus track on a collector's E.P. And, after an absence of several years, it was important to show that Dissection was still a force to be reckoned with.
A somewhat pointless example would be Sodom, who re-recorded the classic In the Sign of Evil E.P., along with a handful of other songs that were, supposedly, meant to be recorded back in 1984. The sound does hearken back to the old days and maintains a raw, old school feeling. However, the re-recorded songs do not compare, favourably, to the originals and the new songs aren't good enough to justify this project. Since I don't recall these songs appearing on the demos that preceded the E.P. or the albums that followed, part of me wants to say that the guys just felt nostalgic for the past and decided to write some new songs in their old style, and the whole back story was merely a gimmick. I have no proof of that, obviously, but it does seem odd that they would be unable to record all of the songs that they had planned to, and then just tossed them aside and didn't bother to include them on Obsessed By Cruelty, for example. Whatever the case, at least they made an attempt to keep the raw sound and atmosphere when they did this.
If one wants to see just how disgusting re-recording classic material can be, look no further than Testament and Anthrax. On First Strike Still Deadly and The Greater of Two Evils, respectively, each band ripped through several songs from their classic period and raped them, thoroughly. Curiously, neither band had performed at quite the same level for some time, and revisiting these old songs showed that they were still capable of playing with a decent level of energy and precision. Still, trying to give 80s Thrash Metal a modern feeling is a crime beyond all others. In the case of Testament, the thicker production ruins everything and Chuck Billy's 90s vocal style does not fit well with the old songs. As for Anthrax... John Bush should never try to cover the Belladonna-era, or the Turbin-era, for that matter. He really seemed to try his best, but his style is nothing like either of those guys. The modern production ruins the feeling of the songs, as well. If the band wanted to revisit their glory days, they'd be much better off simply returning to their roots, rather than raping the past. A band like Anthrax should stop making trendy groove nonsense and go back to thrashing as they did on Fistful of Metal and Spreading the Disease. Take a cue from Bathory; when Quorthon decided to return to the Viking Metal sound, he didn't re-record Hammerheart, he wrote brand new material in the same vein, and ended up creating two more classic records.
While re-recording a song within a few months or so is one thing, going back a decade or two is rarely justified. Similarly, replacing bass or vocal tracks, or completely remastering the albums to give them a modern feel, thus stripping them of their very spirit, all of these things are crimes against music. Most bands would do well to leave the past alone. Of course, musicians and technology may improve with time, but that doesn't necessitate going back and ruining old records. They represent a moment in time that was captured and preserved and, nine times out of ten, the atmosphere and feeling of the original is not worth sacrificing for any reason.