Not all of the developments on Trey Songz' fifth album are positive.

The singer has never been too proud to release shamelessly crude club music, and "2 Reasons" manages to outdo earlier hits "Say Aah" and "Bottoms Up" to the point of being parody-proof.

Forty seconds in, Trey proclaims "I only came for the bitches and the drinks," repeats the phrase over 20 times, and follows "Baby, get your glass up" with -- guess what -- "Baby, get your ass up." It's the pop-R&B equivalent of Gangstalicious' "I Got Shot" (which was a pointed spoof).

Trey can deflect the criticism by pointing at its commercial success; before Chapter V was released, the song was in the Top Ten of Billboard's Hot R&B/Hip-Hop chart.

It joined the album's first single, "Heart Attack" -- a bleepy/weepy ballad delivered with relatable and convincing conviction.

Not many artists can achieve the same level of success with such contrasting material.

Even fewer under-30 R&B vocalists bother to temper boasts of bedroom aptitude by singing about what they can do for -- rather than to -- their women.

That's one advantage Trey has over the majority of his peers, as heard in "Forever Yours": "I hope she tell me what she want, just so I can do whatever she says." Just as significant, the contemporaries who might call him soft for such a line probably aren't clever enough to come up with something as slyly tough as "And no, it ain't my crib, but I'm comin' home/Daddy's little girl, I'm-a treat you like you're grown." "Playin' Hard" and "Fumble," introspective and self-critical, are two of the album's most resonant songs and provide more depth, even though the sentiments are probably fleeting.

Those who tire of the coarse metaphors, disrobing scenes, and "panty wetter" talk can get lost in the sleek, layered work of Troy Taylor and his associates.

The snaking rhythms are just as remarkable as the hypnotic synthesizer textures.