What changed in season 7?
 

There is such a difference in season 7 compared to the 6 previous seasons that it makes me wonder what happened?

The stories all revolve around aliens or other ridiculous things (even more than the other ridiculous things that happened), the writing is poor in general with a lot of forced humour.

Does anyone know if there was a change behind the scenes? Writers, director, producer? It just seems like something must have changed.

wait! Are you saying that season seven was bad? Because it is considered the most solid season of the classic series since the five part pilot episode arc, with it's throw back to the tone of those early episodes. Also David Wise wrote most of those episodes.

I think you're referring to those "European Vacation" episodes which were really written around the time the normal Season 4 episodes were made, which as we know had those ridiculous plots. As far as for the proper CBS, Donatello and Raphael slice Season 7, there were some changes, and I think they were actually for the better for the most part. The sillyness of the earlier seasons still remain, but in a reduced manner leading to more actions. Many characters are used for the final time in the series (Neutrinos and many villains in Night of the Rogues), and even the non-Shredder episodes unlike Seasons 4-6 are somewhat more focused on action. April's and Splinter's roles are reduced quite a bit in this season with fewer of those news reports compared to the earlier seasons, with April and Splinter not appearing in two and six episodes, respectively, meaning that the turtles have fewer allies for support. Also, all but two episodes take place at night in this stretch, continuing the trend from Season 6. Like the Season prior (Season 6's changes), the background music introduced is somewhat darker and more action-oriented than the previous seasons while eliminated some more cues from the earlier seasons, while still keeping the memorable ones such as the Technodrome, Battle Theme, Channel 6, and Turtlecom cue. The firearm sound effects change as well and carry on through the Red Sky seasons. I'd rank it the fourth best season of the show after 1, 3, and 2, and easily could of have more episodes with characters such as Scratch and Hot Spot (though it would have lowered their value considerably).

David Wise wrote every episode of Season 7. And it was probably the best written season of the series since Season 1.

To this day I wish the entire original series could have been written the way Seasons 1 or 7 was. As good as the show was, it could have been even better.

There was no real change, David Wise was still the show's primary writer. The show was starting to become more harder-edged around this time because Batman: TAS and Power Rangers was kicking it's butt

Season seven is one of the best in the show's run. I have no idea what your problem is with it.

I noticed a lot of the red sky music was actually introduced in season 7.

Season 7 rocks. The action/animation is very good, the stories are pretty interesting, and it's leaps and bounds ahead of seasons 4, 5 and 6.

There seems to be a lot of love for season 7, but personally I hate it. There is just something "off" about it.

I've always found season 3 to the perfect example of the OT and season 7 is just too far from it. Even comparing it to season 1 the episodes just aren't as good. They had clearly run out of ideas and were just grasping at straws with all those alien stories. And I'm not talking about the European vacation episodes since I know they were made earlier.

Even Raphael's jokes seem so forced and boring.

Why the hell are you complaining about aliens in Season 7 when the ones from Seasons 3 and 4 were usually random and throwaway?

The Starchild ep from Season 7 is one of my favorites. It's laughable to say they ran out of ideas, more like David Wise was free to do what he wanted.

Some of my favorite episodes are from season 7. Night of the Dark Turtle, The Legend of Koji, White Belt, Black Heart, Night of the Rogues, Revenge of the Fly, Dirk Savage: Mutant Hunter, Invasion of the Krangazoids, Combat Land, Shredder Triumphant are all great.