Since 1988, there's been only one Christmas Day that Jon Solomon did not spend at Princeton University radio station WPRB playing unconventional holiday music till he reached the point of exhaustion.

In December 1996, the host of the Annual 24-Hour Holiday Radio Show - which will be heard, as ever, on 103.3 FM from 6 p.m. Christmas Eve till 6 p.m. Christmas Day - was graduating from Northwestern University.

That year Solomon celebrated by driving to California.

"I found myself in the middle of Nebraska on Christmas Day," the 34-year-old Princeton native recalled this week. "And I realized I made a horrible mistake. 'I shouldn't be here,' I said to myself. 'I should be there.' And all the next year, people came up to me asking, 'Where were you last Christmas?' "

For Solomon, there is the studio of WPRB, where he works as a management consultant and hosts a weekly indie-rock show from 7 to 10 p.m. Wednesdays (it can also be heard at www.wprb.com).

He's been on the air since he was 15, when he was regularly putting in requests to Eddie Mosh's punk show Decline and Fall. "There are songs from that show I've still never been able to ID," he says, wistfully. "There was one that went: 'Rigor mortis, my baby's dead, stiff as a tortoise.' I'd love to be able to find out who that was."

Impressed, a program director put him on the air. When the student DJs went home that holiday season, the Christmas Eve shift was open. Solomon, who is Jewish, took it, and stayed on for more than 10 hours of rock, jazz, classical and blues.

The next year, he went the full 24. And ever since, he's been amassing an enormous collection of holiday music that steers clear of the obvious and overplayed.

You won't hear Bing Crosby's "White Christmas" or Dr. Elmo's "Grandma Got Run Over by a Reindeer." But it is the place for such classics as Fishbone's "Slick Nick, You Devil You" and Neko Case's "Christmas Card From a Hooker in Minneapolis."

Despite his affection for obscurities such as Wall of Voodoo's "Shouldn't Have Given Him a Gun for Christmas," Solomon doesn't eschew tradition. He just likes to hear it tweaked, as with Beck's "Little Drum Machine Boy" or the Vandals' "Oi to the World."

His marathon has no official listenership numbers since 'PRB doesn't subscribe to Arbitron's rating service.

Solomon, who lives in Lawrenceville, N.J., with his wife, Nicole, to whom he proposed during the 2002 show, soon gathered so much music that he says he could play a show twice as long.

Collectors inundate him via the Internet - "I had one guy from San Diego send me 450 mp3s on Monday." The DJ, who also runs the indie record labels Comedy Minus One and My Pal God, figures he has 22½ hours of new favorites to choose from.

This year's choice selections include a 20-minute radio play called "Christmas Shopping" by Looney Tunes voicer Mel Blanc, and an oddball 1980s recording called "A Toast to Christmas" played entirely on singing glasses. "Stuff like that I get pretty excited about."

It's a busy time of year for Solomon, who does a music podcast for the Philadelphia City Paper called Local Support and has an alternate identity as a sports reporter at www.princetonbasketball.com.

During the marathon he avoids having too much sugar or coffee, but has "something to keep me busy every three or four minutes."

This year, he'll be accompanied by indie filmmaker Mitchell Kezin, who will be shooting him for a documentary called Jingle Bell Rocks. He needs to stay alert for regular late-night callers phoning in for the Flaming Lips' "Jesus Shootin' Heroin" or H Town's "Knockin' Boots for Christmas."

Even though he's fired up when he finishes, he soon collapses. "One year, I fell asleep in the bathtub at my parents' house. That was pretty embarrassing."

Being Jewish, Solomon says, "has made it easier in some regards to have a greater appreciation of the music as music. And it's hard to argue with the sentiments that go along with Christmas. Who doesn't like family, or spending time with your friends, or annual traditions?"

For discerning holiday music fans, Solomon's show is an annual tradition to cherish.

"A lot of the stuff I play," he says, "is just to say, hey, these songs are really good. Or really interesting. Or so terrible I have to share."

Contact music critic Dan DeLuca at 215-854-5628 or ddeluca@phillynews.com.