With each season, Idol trots out an entertaining theme night in which contestants select a song that was released in their birth year. And with each progressive season, it puts the contestants at a greater disadvantage.

Why? Because the majority of this year’s singers were born in the musical dead zone known as 1984-1989. Trust me, I was making my living as a musician during this stretch, and the pickin’s couldn’t have been more slim.

This was reflected in the song choices on tonight’s show, which generally ranged from dull to dull-but-well-sung.

Oldest contestant Danny Gokey went first, enjoying the distinct advantage of having been born in 1980 — a rather alive time in terms of the musical underground. Though Danny was appropriately dressed in a skinny tie, he completely skirted the rules by singing the 1961 chestnut “Stand By Me,” claiming he was doing the 1980 version by country star Mickey Gilley. Yeah, right. Despite being a cheater, Danny sounded strong on the song, even if the jumpy, schizophrenic arrangement was more befitting a mid-priced Vegas hotel lounge.

If you thought Danny’s arrangement was terrible, say hello to Kris Allen. Saddled with a 1985 birth — arguably the worst year in modern music history — Kris chose the repetitive throwaway track “All She Wants to Do is Dance” by Don Henley. It was an over-arranged, overbearing nightmare. The blaring horns, smooth-jazz changes and funk beats rendered the normally outstanding Kris practically invisible.

What happened to Lil Rounds? Ever since adopting a fresh haircut her vocals have gotten increasingly weaker. She is like the diva version of Samson. Lil seemed conceptually on-track with her choice of 1984’s “What’s Love Got to Do With It.” But she merely mimicked Tina Turner, without the Grammy winner’s innate ability to project in her lower range. It wasn’t bad so much as it was irrelevant.

Fresh off the North Carolina men’s basketball victory, NC student Anoop Desai celebrated by choosing the Cyndi Lauper ballad “True Colors.” Maybe it was the true Carolina blue that inspired him because Anoop sounded heartfelt and confident on the 1986 track. (He was quick to point out he shared the same birthday as Idol winner David Cook.) Still, it was easy to visualize Anoop wooing the sorority crowd at the Tar Heels counterpart of Rock Chalk Revue. How that potentially translates to pop stardom is anybody’s guess.

Oh god, it’s Scott MacIntyre. And he was born in 1985! Gack. Having already played the Phil Collins/Billy Joel card the previous weeks, Scotty tried to “rock it up” Survivor-style. No, not the competing reality TV juggernaut — the actual band Survivor. Since “Eye of the Tiger” was three years too early of a choice, Scott picked “The Search is Over.” He even strapped on a guitar and threw some bar chords into the mix. It was simply awful. Scott is not a rocker, he does not have a rock voice, and, quite honestly, Survivor is hardly a Rock and Roll Hall of Fame candidate to begin with. The performance proved that not only does Scott lack vision, he also lacks taste.

It’s shocking enough that there’s an Idol contestant having made it this deep who was born in the 1990s. Equally stunning is how freakin’ good Allison Iraheta is. Her age actually gave her a tremendous advantage, as it put her birth year at 1992 — a time when popular music was experiencing a renaissance on several fronts. She went with a safer selection than needed, but her rather faithful rendition of the delicate Bonnie Raitt ballad “I Can’t Make You Love Me” proved a decent fit. Like Bonnie, Allison possesses loads of raspy character. She even sold the lyrics, which have a mature, world-weary gravity to them.

Matt Giraud proved that if you dug around enough you could actually find a passable cut from 1985. “Part Time Lover” isn’t considered one of Stevie Wonder’s top 10 catalog songs (or top 20, even), but it might as well have been “Eleanor Rigby” compared to some of the other song choices from this Live Aid year. Matt even effectively donned a Justin Timberlake hat in his attempts at appealing to a greater demographic. As usual, his range and vocal tone were spot-on.

Adam Lambert didn’t even appear this week — if you recorded the show and watched it back later. The hour-long episode cut off immediately following the judges’ hasty comments about Matt. Thankfully, YouTube came to the rescue, capturing Adam’s haunting spin on “Mad World” by Tears for Fears. It’s hard not to be a little creeped out by the 1982-released song, because for modern audiences it’s so inextricably linked to the sinister cult flick “Donnie Darko.” But even if Adam somehow were to get voted off next week, the judges will use the long running time of the show as an excuse to use their “judges save” pass. For all practical purposes Adam is immune this week. He has found the “Survivor” equivalent of the “Immunity Idol.”

Bottom three prediction: Anoop Desai, Scott MacIntyre and Lil Rounds.

Loser: Lil Rounds.