When it comes to Oscar’s original score category, is there such a thing as momentum for potential nominees? Are the 236 voting members of the music branch (all composers, songwriters or music editors) susceptible to buzz about the entries? Do they care about early critics’ awards?

Nobody really knows. But there are telltale signs every year that point to certain trends. There are favorites, there are up-and-comers and there are inevitably dark horses in the race. This year is unlikely to be any different.

In the pole position

French composer Alexandre Desplat would seem to have the most momentum going as we edge closer into the Academy’s announcement of the nominations Jan. 25, with a Golden Globe nom and Broadcast Film Critic win for the classically styled “The King’s Speech,” and an L.A. Film Critics laurel for the suspenseful “The Ghost Writer.” (He’s also getting attention for scoring the recent “Harry Potter” film.) “King’s Speech,” already talked up in many quarters for Oscar consideration in multiple categories, would seem to be Desplat’s ticket for a fourth time to the ceremonies.

Similarly positioned is the vastly different Trent Reznor-Atticus Ross effort for “The Social Network,” which tied with “Ghost Writer” for L.A. Critics honors and also managed a Golden Globe nom. But will the traditionally minded members of the music branch vote for the industrial-rock and electronica sounds of the Nine Inch Nails frontman?

And if they don’t, will there be an outcry to match previous Oscar spurnings of the likes of Radiohead’s Jonny Greenwood and Pearl Jam’s Eddie Vedder?

A.R. Rahman, who won 2008 Oscar song and score honors for “Slumdog Millionaire,” is in the running with “127 Hours,” not just because of his Globe nom thus far but also because the film demanded a lot of music to help dramatize Aron Ralston’s ordeal in a Utah canyon.

The Ronni Chasen factor

Hans Zimmer is also a formidable presence in the race for the massive musical dreamscape he fashioned for “Inception.” He’s already got Globe and Grammy noms along with a handful of other critics’ nods — in part because his longtime friend Ronni Chasen worked overtime on his behalf before, during and after “Inception’s” July release. No score all year long got so much attention, and it continues to pay off.

Publicist Chasen — whose Nov. 16 murder continues to resonate through this awards season — was also trumpeting another longtime client, Elliot Goldenthal, for “The Tempest,” setting early screenings and sending CDs in hopes of generating interest. Negative reaction to the film, however, may have dimmed its chances.

Don’t discount the Chasen factor, however: She was also promoting Harry Gregson-Williams (and partner David Buckley) for “The Town.”

While no one seems to be talking much about the Ben Affleck heist movie, remember that Chasen helped pull off a surprise nom last year for composing partners Marco Beltrami and Buck Sanders for “The Hurt Locker.” Besides, Gregson-Williams is overdue for Oscar attention.

Also making noise

“How to Train Your Dragon,” already an Annie nominee for composer John Powell, this grand score for the animated DreamWorks fantasy could mark Powell’s first Oscar nom, too. The fact that DreamWorks sprung for thousands of “Dragon” CDs in the Nov. 17 Daily Variety can’t hurt.

“Alice in Wonderland,” whose colossal b.o. take could translate into recognition for composer Danny Elfman, and also has a Grammy nom on its resume and is getting ancillary attention for a soon-to-be-released 16-CD box set commemorating Elfman’s 25-year collaboration with “Alice” director Tim Burton.

“Never Let Me Go,” Rachel Portman’s quietly hopeful music for the downbeat film about people cloned specifically to be organ donors, won top honors from San Diego film critics. The London-based Portman — the first woman to win a scoring Oscar — recently made the L.A. rounds on a rare publicity tour for the film.

“Tron: Legacy,” which can boast the first score soundtrack in five years to debut in the Billboard Top 10, is one of the more topical contenders given its alt-pop sensibility. And if the children of branch members urge their parents to vote for Daft Punk’s hip electronics-with-orchestra minimalism, it might sneak in.

In the hunt

“Waiting for Superman,” Christophe Beck’s score for the acclaimed education documentary, is a Hollywood Music in Media winner. But it’s an Academy longshot — no documentary score has been nominated since “Birds Do It, Bees Do It” in 1975.

“Get Low,” Jan Kaczmarek’s lively bluegrass backdrop for the Robert Duvall character study set in 1930s Tennessee, is further testament to the versatility of the Pole with the avant-garde background.

“Rabbit Hole,” Anton Sanko’s intimate chamber score for the grieving parents played by Nicole Kidman and Aaron Eckhart, has thus far not been singled out for awards, but Sanko is well-liked among his peers.

“Mao’s Last Dancer,” the arthouse hit based on the story of a Chinese ballet star who defects to the U.S., features a classically oriented, Eastern-flavored score by Australian composer Christopher Gordon.

“Biutiful,” from two-time Oscar winner Gustavo Santaolalla (“Brokeback Mountain,” “Babel”), has so little music over its two-and- a-half-hour running time that it might not be seriously considered.

Out of contention

“Black Swan” (based mostly on Tchaikovsky) and “True Grit” (based largely on 19th-century hymns) have been disqualified by the branch exec committee as not sufficiently original. Both “The Fighter” and “The Kids Are All Right” are so song-heavy that the minimal scores in both are ineligible. Disney decided to enter songs, not scores, for both “Toy Story 3” and “Tangled.”