Billed as Prince's most controversial album -- at least by his press agency and label -- upon its release in the fall of 2001, The Rainbow Children was arguably his most curious album to date, which isn't necessarily the same thing as controversial.

It could have been controversial, that's for sure, given that it follows his conversion to the Jehovah's Witnesses and that it trumpets his faith, over the most elastic, jazziest backing music he's made.

If Prince hadn't marginalized himself through his record company battles, multi-disc sets, and botched superstar comebacks, this could have been genuinely controversial, since people would be paying attention to what he's doing.

As of 2001, nobody outside of the diehards -- those who sign up for the Paisley Park subscription service and those that will seek out an album like The Rainbow Children, which was initially only available through the Internet -- was really paying enough attention to listen to this record, since they were the only ones to sit through the cascade of arcania he turned out after his liberation from Warner.

Since they're so deeply immersed in this work, they would realize that musically The Rainbow Children is his most cohesive set since The Gold Experience, and the only one to really push past his traditional limits since then (which, admittedly, is still much more imaginative).

And, you know, that's really too bad, because as a musical experience, this is pretty rich, demonstrating not just that Prince knows no borders, but that his music effortlessly mutates within the course of one song, perhaps drawing from his standard book of tricks -- jazz fusion, smooth soul, lite psychedelia, hard rock, and funk general weirdness -- but always sounding unpredictable and rewarding.

It's too bad, then, that the very thing that inspired the album for its creator is what will turn off even those diehards that stuck with him this long, seeking out this album -- namely, its religious views.

It's not that Prince has become a Jehovah's Witness -- any objective listener really wouldn't care -- but it's that his message doesn't support the music and doesn't fit with the sounds or the approach; it's hard to shut it out, not just because the words are so prominent, but because they're delivered in so many different voices (most distracting of all, the electronically altered basso profundo voice last heard on the decidedly secular "Bob George"), often in short, two-minute songs.

This becomes a little overwhelming about halfway through, when the opera comes in on "Wedding Feast," reminding us that this is indeed a concept album, then delving into three eight-minute jams to conclude the record.

It all winds up as a bit much, but it doesn't erase the musical facts: this is Prince at his most focused and rewarding in a long time, since Emancipation really.

Too bad nobody outside of the diehards cares at this point.