Will it go out gleefully or with a down beat? "Glee" fans find out Friday night as this song-and-dance melodrama finishes its act.

Concluding its run with a two-hour finale on FOX "Glee" leaves behind a remarkable legacy.

First of all, it dared to try something that had seldom if ever worked on series television: Mix episodic narrative with musical production numbers. It set those performances in the context of a show choir, called New Directions, at the fictitious William McKinley High School, a setting replete with stories about growing up, self-acceptance, perseverance and dreams.

"Glee" did something else few would have thought possible: It helped make glee clubs cool.

And it served as a platform for new talent, launching such stars as Lea Michele while giving wide exposure to veterans like Matthew Morrison and Jane Lynch, with guest appearances by a broad range of celebrities that included Helen Mirren, Lindsey Lohan and Ricky Martin.

Pop music — both new and well-established — reached new audiences, both on the show and through sales of more than 50 million songs and 13 million albums under the "Glee" brand.

While it was demonstrating a viewer appetite for musical theater among its audience, "Glee" accomplished one more thing: It highlighted, and even helped normalize, young people traditionally deemed marginal both in real life and on TV. Among the characters included in the "Glee" big tent was transgender girl Wade "Unique" Adams. Tolerance, or at least reaching for it, was a "Glee" hallmark.

During its rollicking run, "Glee" confronted real-life drama, notably the death of cast member Cory Monteith. A breakout star who played singer-quarterback Finn Hudson, he had struggled off-camera with substance abuse. Then, in July 2013, he died at 31 of an accidental alcohol and drug overdose.

That October, "Glee" said goodbye to Finn (whose death, never described, was written into the series) while paying tribute to Monteith in an emotional farewell episode where reality intruded all too vividly on the show's make-believe tale.

With the "Glee" series finale, reality will intrude once again: For the characters at McKinley High, as well as the audience that has followed them for six seasons, graduation day is nigh.