A predictably enormous audience tuned in for the final night of competition on Fox's American Idol Tuesday with finalists Taylor Hicks and Katharine Mcphee each performing three numbers. The penultimate episode (final results are due to be announced tonight) produced a 19.2 rating and a 30 share, representing 30.63 million viewers. The show also provided a potent lead-in for Fox's House at 9 00 p.m., which scored a 16.5/24. The two shows left the competition in the dust. CBS, which aired the Country Music Awards throughout primetime, averaged a 6.8/10. ABC offered Stephen King's Desperation , which drew a 5.5/8, while NBC's Most Outrageous Moments scored a lowly 3.6/5 and the conclusion of the miniseries Apocalypse wound up with a 5.0/8.