Which TV series went through some major tonal changes during its run?

Happy Days

MASH

Does Orange Is the New Black count?

The Office. The early seasons were quite effective because they captured a major aspect of office life : you spend all day around people who you have nothing in common with and would likely never befriend outside of work. Later on the relationships between the Co workers became ridiculously intimate, and I'm not just talking about the office romances. The entire office seemed to have no social life outside each other.

And then they added the James Spader character, who seemed like he emerged from a different TV show. The other characters actually seemed like recognizable types you would meet in a middle American office. Robert California seemed like a oddball new agey type working in San Francisco. His presence was actually jarring and might have worked in another type of show but not the office.

Glee.

Baywatch Nights.

Season One was Mitch (David Hasselhoff) as a Detective when he isn’t a Lifeguard. He spends his nights fighting crime.

Season Two was about Supernatural beings, like The X-Files.

Dynasty. Drama season one. Campfest thereafter.

Almost every show does if it continues after the original creative team moves on. The vision is lost, the new team has to show off. Sex and the city is one of the best/worst examples of this

Family Matters.

Originally about a black family in Chicago and then became about their annoying neighbor.

SATC changed tones when SJP became Executive Producer.

Melrose Place. Season 1 was boring earnest drama, then it went more soapy and got crazier with each season.

Roseanne, after they won the lottery.

MASH. It started out with a laugh track, but then it became all serious and turned into the Alan Alda Show.

It's Always Sunny in Philadelphia.

Season 1 the characters were roughly normal people and there was no Danny Devito.

They become insane assholes moving forward.

Golden Girls. It started out being a show about 4 seniors, dealing with senior type issues. And it morphed into more a traditional sitcom.

The Lucy Show. It started out being about 2 women without husbands raising their kids together and doing funny stuff. Then it became about a widowed woman in LA causing problems for her boss and trying to get into show biz.

I came to say MASH and Happy Days but R1 beat me to it.

It's funny, Happy Days started out sans laugh track, which gave it a very surreal, atmospheric feel to it. But then it got a laugh track added later to lighten it up. And As R11 points out, MASH started out with one and removed it to make the show have more gravitas.

Facts of Life. It was supposed to be a sitcom spun off from Diff'rent Strokes to showcase the talents of veteran actress Charlotte Rae. Then Natalie got raped and Cousin Gerry arrived and it was more soap opera than sitcom. It became the NBC Afterwork Special.

A Different World.

It was a spin-off of The Cosby Show and Denise Huxtable focused, and then for season 2 became an ensemble series that morphed into the Whitley show

Remember when Edith almost got raped on All In The Family??? There's a tonal shift for ya.

A lot sit coms start off light and move into deeper territory in later seasons. Topical stuff. Sociological explorations.

Smash. Season 1 was a soap opera about putting on a Broadway show with the cliffhanger that the lead actress takes a handful of pills. Season 2 they "Glee-ed" it up and it became Fame/Glee with no melodrama.

Dark Shadows

Originally a rather slow paced, character driven drama centered around a family who live in an old, creepy mansion with their many dark secrets. Then the supernatural, which was only hinted at during the beginning of the series, was incorporated and there was no going back. Along came vampires, ghosts, witches, werewolves, a Phoenix, Frankenstein monsters, time travel, you name it....

Moonlighting

"Newhart." The first season relied heavily on Kirk and the diner; after they ditched that character and brought in Stephanie and Michael and the Darryls, the entire dynamic changed.

Doris Day on The Doris Day show suddenly decided to smother her children during the season 3 hiatus, moved to San Francisco, put on a Morton Salt Girl outfit and started living a whole new life.

Change for the better, R23!

R20 I was going to say Dark Shadows too. It started out as Gothic Romance and morphed dingo Gothic Horror.

It's funny how Happy Days started out as a show about life in the 1950's, but eventually ended up looking like the late 70's, even though it was still only taking place in the 60's.

Also, during the first season of the Andy Griffith Show, Andy Taylor was a total yokel. They changed his character to be a bit more savvy, but by the final season he came across as really irritable and serious all the the time.

Falcon Crest was schizophrenic in its later years; from camp in Seasons 6 and 7 to family drama (about the ag workers!) in Season 8 to pitch black film noir in Season 9, which was quite good but nobody cared by then. Gregory Harrison was HAF.

Wonder Woman

Well at least there are two examples from this century.

Alias. When they focused on the Rambaldi shit toward the end it felt like a completely different show. I much preferEd the kick ass double agent side of things.

The Brady Bunch

[quote]Doris Day on The Doris Day show suddenly decided to smother her children during the season 3 hiatus, moved to San Francisco, put on a Morton Salt Girl outfit and started living a whole new life.

I think that was the strangest shift of all, R23. There was some continuity with Doris still playing Doris Martin, still working for a magazine, and still living in the same apartment (with the great staircase). It was just that everybody she'd ever known vanished and she miraculously became a "swinging single."

SO weird. Well, at least they managed a contrived setup for the annual fashion show with Doris as the only model. (It was okay to lose kids and dogs, but not that.)

Spongebob. Seriously. It was hilarious, dimensional and innovative for three seasons. Once the creator jumped ship, however, it all got very two-dimensional and dumbed-down. Became a stupid little-kid show instead of a cartoon for adults like it was previously.

Also Adventure Time got really bad when they ran out of ideas and turned to using the trope of story arcs that lasted the whole season. Also all the auto-tuned singing in later episodes is super cringe. Started out as such a brilliant, irreverent, unique, hilarious show though.

Ellen started out titled "These Friends of Mine" and her best friends from the first two seasons (Arye Gross and Janice from Friends) were replaced with new best friends Joely Fisher, Jeremy Pivenin the third season.

The character of Audrey, who had previously appeared in one episode the first season, became a main character, as did book store employee Joe.

"Parks & Recreation" followed the same course as "The Office": started as quirky character driven Hellish workplace comedy, then the writers got lazy and had all the characters pairing off. It turned sappy, "I love my co-workers theyre my family" very soon. Stopped watching it.

P.S. Rule of thumb for comedy TV shows: Once the characters start fucking each other, the original humor is dead. Time to cancel.

All In The Family, for various reasons.

[quote]"Newhart." The first season relied heavily on Kirk and the diner;

Kirk was hysterical and I think on for three seasons. After he left, it turned into Green Acres, with Newhart the only sane one in a community of oddballs.

Designing Women turned from a sitcom about Southern women into the weekly Julia Sugarbaker lecture series.

“The Affair” on Showtime.

NBC suits tried to ruin Homicide: Life on the Street by replacing older characters with us; the show survived another three years in spite of our utter incompatibility and horribleness.

The anime TEEN TITANS from the '00s, the one on Cartoon Network (I know there's a current CW live action show, I haven't seen it).

The show started out as a light wacky dramedy in the usual offbeat upbeat style of a typical superhero anime, villain-of-the-week stuff. By the last dozen episodes the plots were getting way deep into mental illness, PTSD, alienation & martyrdom of the teenaged characters and allegorically discussing such issues as cybernetics, rape & traumatic abuse, racial breakdown & the problem of existential evil (and Batman doesn't even show up). It's tonally heavy as the teen/young adult comics from the '90s & '00s, yet it was screened to little Millennial kids alongside DEXTER'S LAB.

The episodes with doomed Terra, the furious vengeful young woman who tries to infiltrate and kill the Titans, hold up as some of the best angsty YA television I've ever seen. The tortured homoerotic episodes with Robin's mania over his former dark mentor Slade/Deathstroke are also fantastic.