List of artists that have never lost quality throughout entire career

One of the brightest on my list is 

1. Depeche Mode. I'm big fan started listening and enjoying them from their very first album "Speak and Spell". I am devoted to their perfection of every song they create in terms of sound, melody, harmony and incredible intelligence. Their music may seem simple, but in reality much more complex than seems. I believe that they're somewhat commercialized, but also believe that they deserve their incredible success. They're indeed Kings of electronic rock!

2. Can (The Can). Every album they released is a journey to their creativity. What are they rock? Jazz? Prog? Their music often can cover all styles of music in one song. It's a blend of jazz-trained drummer Jaki Libezeit, classically trained keyboardist Irmin Schmidt(also conductor and neo-classical composer and film score composer), multi-instrumentalist bassist Holger Czukai and classically trained guitarist and electric violinist Michael Caroli (RIP). It's a unique blend of musicians with extraordinary skills and creativity

3. Dead Can Dance. This artist has plenty of praises and each and every of their album is a unique blend of electronics and earth bound instruments. Lisa Gerrard is known to be a part of Gladiator Motion Picture Soundtrack.

4. Tom Waits. Many would criticize Tom for not singing his own voice, but I'm amused the way he does it with spirit of Louis Armstrong! Yes indeed with spirit instead of just imitating. Embracing the spirit of inspired artist is different and Tom is clear example to that!

Many artists have "arcs" in the quality of the work. Up, then down, hopefully then up again. There is the thought that most have only "so much" in them, some only one album. What a depressing idea for those just beginning. I can think of many bands or singer/songwriters who apparently shot their wad with their first release. Many of my long-term favorites---Ray Davies/The Kinks, The Beatles, The Band, The Dwight Twilley Band (with Phil Seymour), only two or three. I’m in the minority, but only Rubber Soul and Revolver make the grade for me! Some only one---Rockpile, though they did a few more as an ensemble on Dave Edmunds and Nick Lowes solo albums.

It’s the writers I find of interest for the longest stretches---currently Iris Dement, Rodney Crowell, John Hiatt, Loudon Wainwright, Jim Lauderdale, maybe Lucinda Williams (she does too many slow songs), Marshall Crenshaw. Dylan, of course. Performers are Buddy Miller, Emmylou Harris, Alison Krauss, Patty Loveless, The Del McCoury Band, anything by Marty Stuart or Chris Hillman. Hmm, all Country--ish.

The saddest for me are those who stay past their prime---particularly Brian Wilson. Seeing him live in the early 2000’s was about as depressing a thing as I’ve ever experienced. I was morose for days afterwards. Then there are those who finish strong. Johnny Cash!

I have the same feeling for Steve Howe.
He's probably got arthritis affecting his wrists and he can't play clean anymore as he used to play
He doesn't trip, but has trouble keeping sound clean against frets. It happens with aging musicians. Andres Segovia closer to the end of his career also sounded bad.

Haven't thought of George Gobel in decades but when you mentioned him, this quote came to mind:

"Did you ever get the feeling that the world is a tuxedo and you're a pair of brown shoes?"

Yes. I have. 
Bruce Springsteen is an artist whoose work has matured and grown.  lyrically  he's become more complex as well.   I heard some of his recent shows where's he's performed Born in the USA and The River.   I not only saw this music performed in the era of its release, but have recently heard recordings of these old shows. 
His band's  new performance of this old material show an incredible musical advancement over the old shows.   The arrangements are similar but are so much more masterful. 
Excellent call on Van Morrison.

I’d include Andy Summers (especially, post-Police) and Neil Finn/Crowded House.
In Bruce Springstin I saw and heard everything: arrangements, good release management, sound, mastering, good live concert management, but, unfortunately, no music! It seems always to me that music isn't Bruce's cup of tea at all. Song "Born In The USA" heard on car radio triggers my wrist to change station few seconds after it's heard.

..Louis Armstrong as mentioned briefly.

Several great classical musicians

 e.g. Pablo Casals

George was an older more couth version of Rodney Dangerfield.

He mostly talked and joked, but there was a little music there if you hung around long enough.

I loved watching George Gobel when I was a kid, so somewhat jokingly mention him in these forums whenever I feel the levity of such is appropriate (think he may even get a kick out of the posts).

Agree about Springsteen. Also my personal favorites: Paul Simon and, especially, Leonard Cohen. Cohen's last concerts were masterful and kept getting better.
I can't say I've really followed an artists whole career except for the Grateful Dead.  But, here are a few that as of now have not let me down. 
Neko Case
Dan Hicks
Brand X
Gentle Giant

I almost forgot Jimi, start to finish. Of any artist I can think of his was a star I can not help to feel saddened by the what if's
Steely Dan, Frank Zappa, Bob Dylan, Oscar Peterson, Dizzy Gillespie, Ry Cooder, Dire Straits, Mark Knopfler, Willie Nelson, Beatles, Miles Davis, Led Zeppelin, Talking Heads, Frank Sanatra, Joni Mitchell, K.D. Lang, CCR, There are many more but this just came off top of my head.

Some really big names, some my favorites I've left off because the have a few so, so or not so good albums.

Pete Townshend has been doing it for 50 years now. Both with The Who and solo. 
Yes, but solo he has a few clunkers. Their are many great artists and bands but few that little or no clunkers.

Just saw Emo Phillips on a Showtime thing…I had no idea he was still around, and hilarious.
Oh yes, thank you, definitely Billie Joe Shaver, an under appreciated singer, writer AND performer.  Awesome in concert.

Elvis Costello has never disappointed.



Tom Waits

Grateful Dead (OK, debatable, but I'm a die hard!)
I can't think of a single artist, in any genre, that hasn't put out at least one dog. In the long term, anyway.

A good friend of mine, now deceased, used to say:

"Every Beatles album has its "Octopus's Garden".
With new technology today and new training programs available for musicians, I can say that there are plenty of organists that could possibly outplay J.S.Bach even playing his own pieces. Since we can't hear J.S.Bach recorded, we can't really judge...
Remember, history is never precise
Haven't you ever heard the Brandenburg played badly? Sounding like a demented circus calliope on methedrine?

It's a good piece, but it can easily be butchered.
i've never been a massive tom petty fan, though he's had a ton of great singles, but i gotta say that (unlike say, dylan, or the stones) his output has been impressively consistent throughout a 40-year career + he still does it live
Tom Petty than is fraction of Willie Nelson who’s career is way over 40 years.
Drag, a poor performance of Back has nothing to do with Bach himself.
Of course a rock.pop, country "artist" requires little to no talent or musical knowledge .

I’ve heard all the Brandenburg's played at least a hundred times live, never heard a bad performance yet . Neither has anyone else who goes to the best orchestras.

No one has ever said Bach was the greatest organist, all comments made in his life-time did said he was a master .
The most agreed upon  opinion among serious lovers of Classical Music worldwide is that he is the greatest composer who ever lived or ever will live .
Just saw this thread. In regards to new wave music only. I really like the old Depeche Mode but after Alan Wilder left they frankly have been making just childish crap.  DM's music has loss it's soul and the lyrics are simply childish.  With that said, the newly released 101 album on vinyl is fantastic. Some of the bands I think that have tested time are Radiohead, Blur, Tears for fears, U2, Johnny Marr and Echo and Bunnymen.  My taste in music is wide and vast.  Been listening to a lot jazz lately. Wish Coltrane and Monk were still alive. 
Of course a rock.pop, country "artist" requires little to no talent or musical knowledge .
Eddie Van Halen -- heavy metal, hard rock artist classically trained on acoustic guitar

Steve Vai -- jazz, jazz-rock, electronic rock multi-genre artist was classically trained on acoustic guitar.

Andy Summers -- jazz, rock, wave guitar artist former Police guitarist was classically trained by one of the greatest classical guitar maestro Emanuel Barrueco

Jan Akkerman -- classically trained on violin performs as lead guitar of jazz-rock band Focus

Jack Bruce -- classically trained on violin and performed as his most know act at Cream -- blues-rock power trio

Joey DiFrancesco -- jazz organist, jazz-rock -- self-trained since the age of 3 and performing since age of barely 7 at the stage (is there any talent?)

Irmin Schmidt -- electronic rock, kraut rock keyboardist and pianist -- alumni of Stockhousen Conservatory as pianist and orchestral conductor. Stockhousen Conservatory is school of innovative music and Jazz in Germany, but it also provides classical training. One of the most unusual schools of music in the world, but bare in mind that classical music rootes mainly from Germany and Austria and I believe still continue to add on...

There are many and many more rock or other ganre artists that literally infused J.S.Bach in their tunes and improvisations -- YES indeed he's one of the greatest, because his music still influences the most current tunes you hear -- just need to realize and just need to optimize judgments towards definitions of talent and musical knowledge. 

Country artists vary between family musical training and various schools of art. I may not find myself enjoying most of the country music, but I do find myself respectful to country artists skill to play instrument. When I hear Ricky Scaggs reefing acoustic guitar, I want to make it lowder, but when I hear his typical country style voice, I may want to shut it all the way down:-)

Classical music even nowdays still evolves, but not finding large enough listener due to commercial media. There are still classical composers of today finding their place mostly in the movie soundtracks. One of my favorite is Maurice Jarre.

I agree with @schubert , Bach was an one of a kind genius. His compositions are complex and beautiful. Anybody who plays the piano would tell you the same. 
czarivey. You seem totally unable to grasp  that in adult conversation some things are so obvious that the norm is to not  state them .
Of COURSE there are people in pop/rock, even country, that are talented and well educated as well.
However it is quite CLEAR that above is optional !
Not so many.

Banco del Mutuo Soccorso (- their 80´s stuff)  feat. Francesco di Giacomo RIP

Practically all RPI. Well, the 80´s wasn´t their finest hour but was it to anyone really in Prog. The early 80´s was rock´s decline anyway.

Ennio Morricone
Keith Emerson RIP
@schubert ,

it is quite CLEAR that above is optional !

What about Mozart who revealed his talent at the age of 7?
It looks like training was indeed optional for him and his music isn't so simple as well.
Later on he learned how to place his own music on our traditional western 5-line staff, but before that he was just like Art Tatum not knowing single note and he learned to sing prior he started talking perhaps in his mother's womb.

Today we have similar talents that play various types of music and sing, but not too much classical. The classical music performances are substantially more structured and strict today. The classical musician is expected to provide clean and precise performance rather than personal interpretation often used by self-taught and trained musicians. 
Once Joey Di Francesco  started learning classical piano somewhere in his early 30s, he quit not too far from his start, because it's not his bowl of soup, however he mastered to learn solfegio. 

One thing I can agree on is when there's no talent or training -- there's no music whether it's rnr or classical. The result is not interesting and boring.
As to commercial media, it's looking for talent that can bring profits to the industry so there must be some of both above mentioned to at least certain magnitude.

Mozart studied with the best teachers available , Haydn for starters who, if not his musical equal, was very close to it .

Classical musicians improvise more than you think, Ivan Fisher the leader
of the Budapest Festival Orch ., which is one the very best in the world, seeks players who do. Every player has their own sound , two play a concerto you hear the difference, not better just different .Conductors use different tempos and stress different things . 

Billy Joel now plays classical , he said he was ashamed of playing what he did when he knew better .
It's true with many classical performance ways to define moods and change pace towards benefit of a certain instrument or a sound, but that's not defined as improvisation.
Classical players pay attention to other players and good ones adjust to same . That's improv to me .
Most of Brandenburg Concerti played mediocre or boring perhaps except Richter piano transcription.
Top of the heap ... Sarah Vaughan. She never lost it. Not one iota. In fact, her instrument continued to grow right to the end. Perfect pitch and a voice that emulated a wonderfully lush tenor saxophone that tenor saxophone players only wished they could duplicate.

Try the last two cuts of this album, "A Foggy Day in London Town" and I’ve Got a Crush on You" to see what I’m talking about:
I hear you oregonpapa. Here's another Gershwin studio recording with Hal Mooney, a young Sarah and also a cd of the rehearsal cuts to give some insight into how talented and gifted that lady really was, just incomparable. Her voice got a bit smokier and richer as she aged but her interpretative skills just kept growing.
Right you are oregonpapa, I was just thinking about composers .
Schubert, Mozart, Beethoven and Brahms never did either for that matter .
The string quartets Beethoven wrote as he was stone deaf and at deaths door have never been surpassed .
Schubert died at 31 and wrote over 1500 pieces and the best were done in his last 2 years when he was very sick.
His String Quintet in C is the Holy Grail for string players, I heard no less a musician than  Arthur Rubinstein say, with my own ears, he thought it the greatest piece of music ever written .

Los Lobos--I've never heard anything sub-par from them.  They did one album in a style I didn't care for, but I can't say it was bad--just not my cup of tea.

Excellent instance and example of nothing but first-rate work in Los Lobos, tostadosunidos! By the way, I learned of them in a great manner: I went to see The Plimsouls at a little dive on Ventura Blvd. in Studio City named The Garage (it was literally a garage---like a car repair place, converted into a "club") in the mid-80’s, and there was an opening act whose name I had not before seen or heard. They started their set, and my girlfriend and I looked in disbelief at each other---they were grrreat! Yup, it was Los Lobos, who had not yet gotten a record deal. I was an instant fan, and still love them to death.

That girlfriend had great taste in music---her favorite band beside The Plimsouls was The Lyres, her favorite rocker Dave Edmunds. Unfortunately, she turned into a pothead, one thing I cannot abide!

+1 for Los Lobos , one of the few bands I liked .
    Little worse than a pot-head women .