I was just thinking about the subject that some bands started out very underwhelming or worse until one day a key line-up addition (in most cases) or removal (in some) came along and really gave the band what they needed to have something special.

What got me thinking - and made me put the thread in the Tavern - was Tool, whose demo and EP I do enjoy a bit, and whose debut I also enjoy a bit, but could easily do without, and by extension the whole band, had it not been for their fatefully replacing Paul D'Amour with Justin Chancellor on bass. And holy fuck what a huge impact a full and complete rhythm section where the bass player is as versed on his instrument as Danny Carey did to the sound of the band, really solidifying their core while giving guitars and vocals a lot more space to breathe simply by virtue of having a much more solid foundation to stand on. This one line-up change lifted the band from one I thought was okay but could do without, to a band whose existence I am eternally glad for.

When thinking of other examples, I almost instantly arrived at Ministry and the day Mike Scaccia came along. I almost feel like I don't even need to say anything here, everyone who knows them knows what it did to their sound, but fuck, Al did some good stuff before that, but with a strong guitarist the band's sound just exploded. Do you think Al could have come up with the riff to "Jesus Built My Hot Rod" on his own? It's what made Ministry the beloved band they are, and some weak albums aside, the guy will be sorely missed.

When Hellhammer joined Mayhem, he took their sound to a whole new level. In particular in the "Live In Leipzig" album, it's his drumming that holds it all together.

The addition of Steve Howe to Yes. Banks was good and all, having a neat part here and there, but Steve Howe brought that unique mix of lead and rhythm with that beautiful sense of melody and those little western nuances that ruled. Time and a Word was a cool record, but the jump in quality from that one to The Yes Album was insane. One of my favorite albums of all time due to the guitar playing (and of course Chris).

Neil Peart joining for the 2nd Rush album was a key.

On the departure side, Vince Clarke leaving Depeche Mode was huge. I feel like it took a couple albums for Martin Gore to hit his stride as a song-writer, but they definitely wouldn’t have become the band they did with Clarke.

As far as bands not on the archives:

Many people may not know this, but Jim Morrison was not the original singer for The Doors. Keyboardist Ray Manzarek handled vocals during their very early days. And then Jim Morrison joined and became one of the most popular front men in rock history. I love Morrison's voice, and he was definitely a key member of the group. This is shown in the two Doors albums following Morrison's death, which are both very subpar. If I remember right, Manzarek took the vocal spot again for those albums. And many people didn't even know post-Morrison Doors existed (maybe until the partial reunion with Ian Astbury on vocals... but they only played live with him, and that venture was not very successful).

David Gilmore replacing Syd Barret in Pink Floyd. I'm not a big fan of Piper at the Gates of Dawn. I vastly prefer Gilmore's guitar playing to Syd's.

Guitarist Martin Barre joining Jethro Tull. I can't remember the name of the guitarist on their debut album, but Tull changed a lot from that album to Stand Up. Martin Barre was a big part in the change from a blues band to the prog/folk rock band they would be known as.

Bands that are on the archives: Ian Gillan joining Deep Purple, Neil Peart joining Rush, Scott Gorham and Brian Robertson joining Thin Lizzy, Michael Kiske joining Helloween, Uli Jon Roth joining the Scorpions, Diego Valdez joining Skiltron...

I wanted to mention David Gilmour but to be honest I'm not a fan of anything before Wish You Were Here, not even Dark Side of the Moon.

Gilmour without a doubt. There is a charm to the first two Floyd records but when DG really became a key figure the music just took off.

Gilmour's addition to Pink Floyd was necessary rather than an "upgrade" per se. The previous guitarist had checked out mentally and was no longer capable or reliable enough to in the band. Not that Gilmour isn't a great guitarist in his own right.

Not quiet the same, but a similar situation with a couple of the Megadeth guys, who left (or were told to) due to various drug issues. Sometimes its not like replacing the guy makes the band better, but it is necessary if one of the members simply cannot continue with the band for whatever personal reason.

I agree, the drumming on the early Mayhem recordings just wasn't very good.

Gene Hoglan joining Dark Angel certainly changed the band significantly for the better.

Marty Friedman and Nick Menza took Megadeth to previously unheard of musical heights.

Deep Purple obviously improved a hell of a lot with the introduction of the MkII lineup.

John Frusciante was a huge part of what made Red Hot Chili Peppers who they are. Before him, their music was fucking stupid and disjointed, leaning on borderline shit. But, when he was brought into the picture, he added a level of maturity into their songwriting. He basically carried the band, and you could tell that everything he was a part of is nothing short of fantastic (except Mother's Milk, which is somewhat weak) and everything he isn't on, well, sucks. Frusciante gave birth to the Red Hot Chili Peppers that many people have grown to love (myself included), and killed the band with his departure. He is and always was the reddest, hottest, and spiciest chili pepper.

Edit: Oh, I forgot to mention Bernemann and Sodom. Sodom regained their stamina after they hired him, and he's shown huge amounts of influence on the band. He helped cement Sodom's place as one of thrash metal's greatest ever bands, and that's partly because the material with him speaks for itself. They could have fallen down the path of "play our legendary 80's stuff because that's good enough", but they didn't, and that's thanks to Bernemann.

To me the prime example of this is Stratovarius. That band was clinging on the edge of a cliff by their fingers with bad and shitty albums, plus a fiasco and Timo holding a gun to their heads. After all that turmoil and years of garbage what happens? They get some new blood in there to not only perform, but write and produce. Porra and Kupiainen deserve godly praise for making the band the best they've been in forever. A line-up change that they desperately needed if they wanted a resurrection, relevancy, and their credibility back.

I was going to mention Stratovarius. I haven't listened to everything by them, but their new stuff is clearly an indication of a band that has renewed itself after a period of mediocrity.

When Shannon Lucas joined TBDM. Nocturnal was landmark album for the band and his drumming is part of what made it as such. Alan Cassidy has done an amazing job since he came in as well, especially having those shoes to fill.

First thing to come to my mind is Scott Travis replacing Dave Holland in Judas Priest. As most know Holland's drumming was terribly mediocre and in my personal opinion actually held the band back to an extent. Scott Travis was just the kind of person needed to inject some renewed energy into the band.

Iron Maiden replacing Dennis Stratton with Adrian Smith was another bleedingly obvious game-changer.

You are very right in that, John Frusciante made RHCP what it is. Anyway, their new album isn't very bad, the new guy (Josh?) improved a lot with the guitar and the backing vocals.

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Two of the most important line-up changes in the history (IMO) are when Bon Scott joined AC/DC after Mark Evans departure and when Slash joined Guns n' Roses after Tracii departure.

Mark Evans vocals were kinda weak, I just love Bon Scott vocals, he was a very talented singer, but when he died, Brian Johnson entered the band and actually made it what it's today. I think Brian Johnson's vocals are great for the band, but Bon Scott will always be the best singer that AC/DC had, Brian Johnson can't sing "It's a Long Way to the Top", "If You Want Blood (You've got it)", "There's Gonna Be Some Rockin'", "Jailbreak", "Can I Sit Next to You Girl", "T.N.T." nor any Bon Scott's era song as he did. Now, all the albums before Back in Black were mainly blues rock, when Brian joined the band got a less blues oriented style and started to do hard rock with blues influences, anyway, "Back in Black", and maybe "The Razor's Edge" and "Black Ice" are the only good albums that AC/DC released with Brian, all the other albums are just lame and boring.

And Slash gave to the Guns soo many riffs, soo many classic riffs as the riff of "Sweet Child of Mine", or enjoyable solos as the solo of "November Rain", surely GnR would not be as known as it is if Slash never joined. All the albums post-Slash are kinda lame and boring.

ALL the albums post-Slash? Did another 30 years pass for Axl to make a second album without Slash?

And pretty sure it's DAVE Evans, not Mark.

Scott Travis in Judas Priest, Painkiller would have probably been impossible with their other drummers.

Ben Shepherd from Soundgarden. I really like Louder Than Love, but they no doubt peaked with the two subsequent albums.

Although I really like their first albums, I'll say Mike Patton in Faith No More. He just dominated that band after a while.

As usual I'm late to the party so most of my obivous choices are already shot. I'll give it a spin:

- I said "most of my obvious choices", and indeed I'm surprised nobody pointed out Bruce Dickinson joining Maiden, maybe because it's just that obvious. I mean, I love the first two albums, I love what Paul did on those, but we would have bever got the following classics with him still on vocals, more so considering that Bruce was actually much more involved in the songwriting so he helped forge the records in that respect as well.

- Silenius joining Abigor. Granted, vocals are hardly the focal point of black metal, especially when the music is so intricate, but there's no way any album he's been on would have been as effective with Tharen still behind the mic. Similarly, while I do somewhat enjoy Satanized, T.T.'s absence is very clearly felt.

- Gene Adam leaving Iced Earth. I don't hate his vocals nearly as much as everyone else seems to do, but he had no place on material like Night of the Stormrider or Burnt Offerings.

- Shaxul parting way with Deathspell Omega probably precipitated the change in sound which was already underway as Manifestation 2002 proved.

- Dave Grohl joining Nirvana had a pretty big impact on their sound. Hate him and the band to your heart's content, but as much as I love the grittiness of the early stuff, Grohl's drumming is much more powerful and creative.

- More of a switch than a replacement, but Dimmu Borgir got way tighter when they let Tjodalv handle the drums. I like their early stuff a lot, but I still wonder why the hell they bothered to let Shagrath drum at first, since "phoning in" is an understatement. Granted, the music was way slower and sparser back then, but damn.

- Jimmy Page joining The Yardbirds, and especially moving from bass to lead guitar alongside Jeff Beck (who would leave shortly after). It was the first important step in a rather convoluted chain of events which ultimately gave birth to Led Zeppelin.

- Big Boss moving from drums to vocals in Root. Pretty self explanatory if you're familiar with the band's discography.

- Faust joining Emperor, letting Samoth move back to guitar. In a single move they gained a much more tight rhythm section and the guitar team that produced so many classic riffs and themes.

- Harry Wilkens and Oliver Kaiser joining Destruction. They were already a pretty tight band but the precision and intricacy really went up a notch with these guys on board - not to mention Live Without Sense wouldn't have been as massive with only one guitar.

- Noel Gallagher joining The Rain and chagning them into Oasis

- Ulver's trilogy owes a lot to Haavard joining Ulver full time (IIRC he got involved as a session member first, but don't quite me on that).

- Another obvious one I saved for last: Nocturno Culto joining Darkthrone. He has contributed so much all through the band's era that to imagine their legacy without him is unthinkable.

Yes! Forgot about this.

Also thought about adding this, but I love the first album too much.

Nazgul a.k.a. Satanic Tyrant Werwolf leaving Horna and being replaced by Corvus. Nazgul was a rather mediocre vocalist with irritating mannerisms, whereas his replacement is one of the strongest black metal voices of all time. That line-up change also commenced a new period of creativity in Horna, with Shatraug and Corvus working together to create their absolute best material. The synergy was so strong that, before Corvus' departure, Shatraug even said that if Corvus should leave the band, that would most likely mean the end of Horna.

You could say that Ozzy's departure from Black Sabbath was quite important at the time. Dio was able to inject enough energy into that strungout band to create two excellent albums, whereas based on the band's performance with Ozzy lately, that would've seemed unlikely to say the least.

Also thought about adding this, but I love the first album too much.[/quote]

Oh, I absolutely love Bleach the way it is alright. But Cobain and Novoselic were breaching out with their songwriting after that, and Grohl's more active drumming was just the perfect fit.

Actually, in this case I want to defend the original lineup. Poland and Samuelson were awesome players but raging heroin addicts. Mustaine has frequently commented on the fact that that lineup never came close to maximizing its potential. When Marty and Nick arrived, a) they were clean, and b) so was Dave. For a while anyway.

As for other changes for the better:

- Floor Jansen in Nightwish. While the album wasn't their best, she really delivered on the live shows. Anette was not up to the Tarja material but Floor sure was.

- Louie Clemente leaving Testament. Like Dave Holland he totally hamstrung the band with his mediocre, one-dimensional playing. Dette, Hoglan and of course Lombardo were all major improvements and that's when Testament began making truly great albums.

- There's a British hard rock band called Heaven's Basement that I really took a liking to a few years back, and when I looked into their back catalogue it became clear they had really scored a great new singer in Aaron Buchanan. Sadly he left the band, which sucks because the band improved so much with him on vocals.

- Tim Calvert joining Nevermore. DNB wouldn't be the same without him. Damn shame he only did one album with them.

- And how can we forget Bruce Dickinson joining Iron Maiden?

A few more recent ones, not exactly historical, but definitely improving the overall sound:

Recently, Dave Lombardo joined Suicidal Tendencies and on the new record (which is their best in a loooooong time), he is all over the place, giving them so much energy... it's great to listen to. With all due respect to their previous drummers, this was a huge change for the better, IMO.

Another drummer change was Eloy Casagrande getting into Sepultura to very much the same effect, not just live, but on the record as well.

Voivod also couldn't have thought of a better replacement for Piggy than Dan Mongrain. They haven't sounded this good in years.