American Idol RatingsThe Top 13 American Idol finalists’ performance show last night (5.6/15 in adults 18-49, 18.5 million viewers) was up 12% from last Wednesday to deliver another nightly win for Fox in 18-49 and total viewers. Idol was not alone — most originals were up last night against a slew of repeats on ABC, CBS and NBC. A new Survivor: One World (3.2/9) on CBS was up 10% from last week for a season high. It was followed by drama reruns. NBC’s 8-9 PM comedies — Whitney (1.6/5) and Are You There, Chelsea (1.5/4) were also up, by 7% and 15%, respectively — with their ABC comedy competition in the hour in repeats. Following a Law & Order: SVU rerun, Rock Center With Brian Williams posted a 1.0 among adults 18-49 in its latest move to Wednesdays at 10 PM. That was up 43% from the newsmagazine’s airing at 9 PM last week but still well below the other newsgazine in the hour, ABC’s Revenge For Real special (1.4/4). Both programs trailed the CSI repeat (1.8/5) on CBS. With a Modern Family repeat as a lead-in, a new Happy Endings (2.0/5) dropped 26% from last week to a season low. CW’s One Tree Hill (0.7/2) was steady, while America’s Next Top Model (0.6/2) was up a tenth from last week’s low-rated season premiere.