American Idol ends tonight. In honor of the long-running singing series, Deadline spoke with former FOX reality series chief Mike Darnell about the show’s origin and legacy.

Darnell oversaw the series from its launch in 2002 until he left after season 12 in 2013.

Speaking to Deadline, Darnell said he knew the show would be successful when he first saw a bad audition:

Moment one, for me, was the first audition, which was at the Hollywood Athletic Club, in Hollywood; it was very small, we had very few people come out, maybe a couple hundred. That was the first time I had met Simon [Cowell]. I was at that audition with my co-workers and my wife, and this was the first time I experienced a bad audition. And it was so funny, my wife had to run out so she could laugh outside. If I remember correctly, Paula [Abdul] was upset and kind of crying because she did not realize how harsh it was going to be. And it was at that moment I thought, this is unique. Simon and his sensibility of being frank and honest with contestants instead of gentle, I’d never seen that before, and it was never on American television — including Pop Stars and Making The Band [which] were really sweet.”

He added that he doesn’t know if it’s the right time to end the show, but nothing can last forever:

I don’t know whether this was the right time, the 15th season, but nothing lasts forever. And this show was so big, it was so loved, that there’s really not much you can say other than it had an enormously successful ride. I feel, looking back in the annals of television, probably the biggest, longest ride of any show, ever, on television. I don’t know that there’s ever a right time but I think it was the right thing for Fox to do to give everybody a year to sort of say goodbye. I think that was important and nice for the crew and nice for everybody that works for the show and nice for the audience. And you know what? The numbers are still pretty good.”

Darnell also spoke of Idol‘s impact, saying the series will be the “last, great television show”:

Well, clearly it had an impact on almost every performance show that came after it. You know, we now look at three judges as just the most common thing on the planet — it was new when we did it. We now look at the interactivity as something that is part and parcel of everything — it was brand new when we did it, we only had phone numbers. To shift perspective, there was no iTunes, there was no iPhones, it was people on their phones feeling empowered for the first time. So, it had an enormous impact on that drama that dominates reality across the world, which is what we call shiny floor shows, from America’s Got Talent to, obviously, X-Factor to The Voice. And I think it had a bigger impact than just reality television: it is the last, great television show that will probably ever exist at that level, period, in America. I do not believe anything will approach the numbers of Idol. I just think there’s too many other forms of TV, you know, with Netflix and Internet and cable. I think there’s too much splintering now, so even a big hit is going to be half or a third of the numbers that Idol did.”

The two-hour American Idol series finale airs tonight at 8 p.m. ET/PT. 

What do you think? Are you a fan of American Idol? What are you favorite moments from the series? Will you miss it?