An unused idea for a Glee spinoff would have been anything but gleeful. Running for six seasons between 2009 and 2015, Glee was, at one time, a TV phenomenon. Despite attaining such huge success, Glee never produced a proper spinoff series. The Glee Project premiered in 2011, but was merely a reality competition where aspiring warblers could win a stint on the main Glee TV series. Perhaps unsurprisingly, a proper in-canon Glee spinoff was considered at one point, but never came to fruition.
The inherent problem behind the Glee TV show's concept was that, sooner or later, the main cast would graduate from high school. As this milestone approached toward the end of Glee season 3, questions were raised over how the show would continue, and what would become of the characters after their time at William McKinley came to an end. According to Glee co-creator Ryan Murphy (via Deadline), the original solution to the Glee graduation problem was sending Cory Monteith's Finn, Lea Michelle's Rachel, and Chris Colfer's Kurt to star in a New York-based spinoff.
Glee's Planned Spinoff Was A Terrible Idea
The planned Glee spinoff never happened, and Glee ultimately ended up incorporating the graduates' New York storyline into the main show, blending it with a new class back at William McKinley High. Had the Glee spinoff gone ahead, however, it would have surely proven misguided. If Finn, Rachel, Kurt and other original Glee actors starred in a spinoff, that show would have become Glee season 4 in all but name, continuing with the story, characters and journey of the original show. If Glee itself had then moved forward with its brand-new cast and lack of original characters, it would have felt distinctly like a spinoff.
Fox inevitably would have tried to market the New Directions 2.0 as Glee's future, but the fresh-faced newbies would have been in direct competition with the spinoff crew, who had already earned the audience's hearts and investment. Fox could have canceled the main Glee show and focused exclusively on the New York spinoff, but then would have lost the youthful spirit at the heart of the franchise, creating a no-win scenario. Melding old and new casts together into the later Glee seasons offered the best of both worlds - an injection of new blood and a continuation of the familiar.
Glee Should Have Ended After Season 3
The graduation of Glee's biggest characters in season 3 had three potential solutions, none of which were ideal. Those options were cutting the graduated characters completely, using the ditched spinoff continuation idea, or the option Glee eventually used of keeping the original cast in the main show. There was, however, another choice - Glee ending with season 3. In hindsight, graduation seems like a natural conclusion for the Glee story. A group of misfits entered New Directions, evolved into young adults, and departed ready to face the adult world full of hope and optimism.
Anything beyond that, whether it be a new cast or sticking with the originals into the real world, was arguably always unnecessary. Co-creator Ryan Murphy has previously conceded that Glee should have ended with season 5 after Cory Monteith's tragic death, and that sentiment is certainly difficult to argue with. However, Glee ed up a perfect finale already at that point, choosing to soldier on in spite of multiple major graduations after season 3.