Among the surprises of this morning’s Oscar nominations announcement was that only two songs—“Man or Muppet” from The Muppets and “Real in Rio” from RIO—were nominated for Best Original Song, even though 39 had been shortlisted. Why so few actual nominees?

Blame it on arcane Academy rules. To determine the Original Song nominees, the Academy’s Music Branch (a group of 236 musicians including Bryan Adams and Eric Clapton) convenes every year in early January to screen clips of all the shortlisted songs and assign each a rating from 6 to 10 (including half points). A song must receive an average rating of 8.25 or higher to become a nominee. If no song achieves an 8.25-point rating, then there are no nominees. (This has never happened.) If only one song achieves an 8.25-point rating, then it and the next-highest-rated song become the nominees. Which means that either both “Man or Muppet” and “Real in Rio” averaged 8.25 points or more, or only one of them did.

This is the first time only two songs have been nominated for Best Original Song, though there have been a few years, most recently 2008, when only three songs were nominated. The highest number of nominated songs occurred in 1938; ten songs made the cut that year. (These days, Academy rules cap the number of potential nominees at five.)

To be eligible for a nomination, a song must be written specifically for the movie in question and, “a clearly audible, intelligible, substantive rendition … of both lyric and melody” must be presented either in the movie itself or as the first song of the credits. Thus songs from musicals, like The Muppets and RIO, have an easier time of making the cut than songs from non-musicals, which often rely on montages to squeeze in original songs.

Slate pop critic Jody Rosen notes that the dearth of nominees this year comes as a bit of surprise, given that the shortlist included songs by such critical and commercial darlings as Lady Gaga, Mary J. Blige, and The National. (It also included three songs from Dam 999, an Indian epic that hasn’t been released in the U.S. but that was also on the 265-film shortlist for Best Picture.) However, the rules seem to favor songs that are well integrated into their respective films—after all, the voters are given video clips, not audio tracks, to help them decide on their nominations. Are this year’s nominees as impressive as stand-alone tracks as they are onscreen? Take a listen and see what you think:

“Man or Muppet” from The Muppets:

“Real in Rio” from RIO:

Incidentally, this is the first time in three years that Randy Newman—recipient of 20 career Oscar nominations, 12 of them for Best Original Song—was not nominated in the Best Original Song category. If only he had actually written the theme song to We Need to Talk About Kevin, the category might be a little more interesting this year.

Eric D. Snider’s fake Randy Newman theme song for We Need to Talk About Kevin: