Train, "California 37" (Columbia)

Jason Mraz, "Love Is a Four Letter Word" (Atlantic)

Pick your poison: the simp or the cad. Warm and fuzzy or cold and brusque. Pretty lies or ugly truth.

Mraz, well, he would never hurt you. That's been clear for years, but never more so than on his 2008 hit "I'm Yours," one of the most indelible pop songs of the last decade. "I'm Yours" found an unlikely counterpart in "Hey, Soul Sister," released the following year by the band Train. Both were expressions of fealty, and both indicated the continuing vitality of maligned soft rock.

But Mraz and Train, led by Pat Monahan, are not the same, not nearly so, as their new albums show. "Love Is a Four Letter Word" is Mraz's fourth and his most perplexing, and dense, relative to the warm directness of his previous work. For Mraz this is a retreat. Train, on the other hand, appears to have been energized by its brush with resurgent fame. "Hey, Soul Sister" was the band's first major hit in eight years, and "California 37," its sixth album, resides gladly in its shadow, full of equally goofy songs.

For Mraz, loving embrace comes naturally. He doesn't have a powerful voice, but it's reassuring and tender, a good match for his genteel folk and reggae-inflected rock. This album is filled with platitudes and, eventually, psychobabble, dippy even by Mraz's standards. He used to revel in wordplay, but here he's more apt to pun. There's one welcome moment of friction on this album: "Who's Thinking About You Now?" a loose James Taylor-influenced bit of light soul on which Mraz makes his case to a lover under a hint of a dark cloud.

Monahan, on the other hand, is all drizzle and sleet, a clumsy seducer more interested in looking in the mirror than in your eyes. When a woman leaves him on "50 Ways to Say Goodbye," he says he'll make excuses for her absence. Even on the straightforward post-breakup song "When the Fog Rolls In," he sounds smug. These are pickup lines and breakup wishes irresistible only to the person saying them. And yet they're curiously effective. They burst with self-regard, undimmed by even a moment's reflection. On a couple of songs, Monahan engages in a degree of autobiography that remains uncommon in mainstream rock, generally home to bland, frictionless moans of pleasure and pain or personal stories rendered opaquely, so that everyone can feel included.

Mraz has one song with this feel: "Frank D. Fixer," about his grandfather, but it feels like a fable. Monahan's first-person songs feel more specific, more absurd. The album opener, "This'll Be My Year," echoes Billy Joel's "We Didn't Start the Fire," running down a chronology of world events, though in outrageously clunky form, and links them to the evolution of Train.

And then there's the title song, which seethes with resentment at those who would have left him and his band for dead: "Here's to those who didn't think that Train could ever roll again/You were the fuel that I used when inspiration hit a dead end." The candor is insipid, and almost admirable.