Christopher O'Riley loves Radiohead. Only love may not be a strong enough word.

``Go ahead and say it,'' O'Riley says when asked about his fascination with the English band. ``Obsessive. There should be a life somewhere, right? It's really the only music I listen to when I'm not listening for work.''

Radiohead, the deep-thinking fan's rock band, has many followers just as fixated as O'Riley. But he's the only one who's a respected classical pianist and the host of a Boston-based public radio show, ``From the Top,'' that showcases budding young classical musicians.

Now O'Riley brings together the unlikely combination of his classical piano chops and the music of Radiohead on ``True Love Waits: Christopher O'Riley Plays Radiohead.'' It arrives in stores Tuesday, not coincidentally the release day of Radiohead's new ``Hail To the Thief.''

The CD consists of O'Riley playing his own solo piano versions of 15 Radiohead songs drawn from the group's five albums and live EP. It's the only classical album ever to earn a four-star rating from Rolling Stone (Billy Joel's ``Fantasies and Delusions'' managed only 2).

``I connect with Radiohead's music for the same reason I connect with most of the music I play,'' says O'Riley, who's previous recordings range from Bach and Beethoven to Stravinsky and Scriabin to modern tangos. ``I'm always listening for interesting textures and colors and harmonies, and those are hallmarks of Radiohead's style. I wouldn't call anyone in the band a virtuoso guitarist, but you have potentially three guitarists contributing a specific building block in a way that is much more contrapuntal than you find in most popular music. As a classical player, that makes my ears perk up.''

Like many other Radiohead heads, O'Riley discovered the group's experimental alt-rock after the release of the band's critically adored 1997 breakthrough, ``OK Computer.'' He started collecting every recording he could find, authorized and otherwise. Then he began transcribing their songs for solo piano and performing the music as station-break filler on ``From the Top.''

``We started getting e-mails,'' O'Riley says, ``people saying things like, `Gosh, that was really beautiful. Who is this Mr. Head and where can I find more of his music?' They thought it was some composer I had picked up on.

``Or others said, `I thought I knew all of Debussy's music, but I never heard this piece before.' And then they find out the piece is `Subterranean Homesick Alien' by Radiohead.''

Once O'Riley had a dozen transcriptions finished, he performed a Radiohead recital on NPR's ``Performance Today.'' Radiohead fans quickly made the show available via the Internet, sparking interest both in O'Riley and classical music.

``I had Radiohead fans writing me saying, `I see you're playing Mozart and I've always wondered what Mozart's about,' '' O'Riley says. ``It's like all of a sudden they had a friend in the business. Now there's a whole dialogue going on.

``The Radiohead fanboard I've been on most often is called ateaseweb.com, where you'll find 200 Radiohead fans chatting away at any given time of day. People will say, `I know you're into Radiohead. What would you recommend?' I go to some of the music that Radiohead has drawn on, like (Olivier) Messiaen. A song on their new record called `Sail to the Moon' is almost an homage to the violin, cello and piano movement in Messiaen's Quartet. It starts out with this bell-like set of chords.''

O'Riley, speaking by phone from his home in Los Angeles, suddenly begins to play to demonstrate his point. Then he picks up the phone and resumes.

``(Dmitry) Shostakovich is someone else we talk about. When Radiohead played in Berlin in 2000 they used the slow movement of, I think, his 12th Quartet as their walking-on music. So obviously they listen to Shostakovich. And there's some Arvo Part in another new song they do, `2 + 2 = 5.' ''

O'Riley gets excited as he talks about bringing classical and rock fans together in appreciation of good music of all varieties, categories be damned. He believes he's following classical tradition by playing the music he's in love - and obsessed - with.

``I think by playing Radiohead I am revitalizing an activity that's been going on for hundreds of years,'' O'Riley says. ``If Beethoven could be cajoled to sit down at a party and play piano, he didn't trot out his Fifth Symphony. He'd improvise on the popular songs of his day. Lizst took Hungarian folk songs and made them into grand piano fantasies. Bartok recorded hundreds of folk songs, which became the building blocks of his classical compositions.

``Look,'' he says, ``people are right to be skeptical of crossover. When Pat Boone does `Stairway to Heaven,' it's calculated, not sincere. But I don't think of `True Love Waits' as being a crossover record. I think it's like Lizst's `Hungarian Rhapsodies.' Only this is O'Riley's `Radiohead Rhapsodies.' ''

Christopher O'Riley hosts a new taping of ``From the Top'' featuring the New England Conservatory's Youth Philharmonic Orchestra conducted by Benjamin Zander, Sunday at 2 at Jordan Hall. Alas, no Radiohead will be played. Tickets are $15, $10 for students and seniors. Call 617-536-2412.