1.1308858-4099812070
This March 19, 2014 photo shows judges, from left, Keith Urban, Jennifer Lopez and Harry Connick, Jr. on the singing competition series "American Idol XIII," in Los Angeles. (AP Photo/Fox, Michael Becker) Image Credit: AP

A recent time slot switch hasn’t paid dividends for Fox’s lurching American Idol, which reached a smaller audience last week than for all but one episode of its rookie season in the summer of 2002.

Thursday’s edition of Idol reached 8.4 million viewers, the Nielsen company said. Once television’s most dominant show, last week’s results programme barely made it into Nielsen’s top 20 for the week. Wednesday’s show had 9.8 million viewers.

“For a show on that long, there’s going to be viewer fatigue,” said Brad Adgate, an analyst for Horizon Media.

NBC’s The Voice has moved past American Idol as viewers’ favourite music competition show.

Fox a few weeks ago moved Thursday’s Idol to 9pm, although the switch hasn’t seemed to affect ratings. Only the July 3, 2002 Idol had a smaller audience than last Thursday. Among the 18-to-49-year-old demographic Fox seeks, that was the smallest audience ever.

Fox notes that viewership decline is to be expected for a show on for so long and that, except for one year, the audience has been slipping gradually since 2006. Most longtime programmes follow the same trajectory and, even with the slip, Idol is still Fox’s most popular show.

With The X Factor now off the air, Fox might consider bringing the show back to its roots with judges Simon Cowell and Paula Abdul, Adgate said.

A likely scenario is a reduction in American Idol hours on the air. ABC’s Dancing With the Stars, facing a similar decline, condensed the show’s twice-a-week schedule to one, and its new season premiere had 15.4 million viewers last week. Dancing was the second most-popular show on the air last week, behind only CBS’ NCIS.