On the surface, The Mollusk is a return to the panoramic, multi-genre extravaganza of Chocolate and Cheese, but in its own way, it's as much of a concept album as 12 Golden Country Greats.

It just isn't as explicit about its intentions.

Nearly every song on The Mollusk has a nautical theme, buoyed by a heavy progressive rock influence.

Several songs deviate from the theme -- the synthetic new wave pulse of "I'll Be Your Jonny on the Spot" and the frenzied pseudo-country of "Waving My Dick in the Wind" are neither seafaring nor prog -- but there's an unmistakable watery undertow to the record.

Perhaps the loose concept is the reason why The Mollusk is the most concise album in Ween's canon, but it's not what makes the record so impressive.

Like Chocolate and Cheese, The Mollusk could seem like a comedy record to outsiders, but the songwriting and performances are so remarkably accomplished that it is just as listenable after the shock of the humor has faded away.

"The Mollusk," "Mutilated Lips," "The Golden Eel," and "Buckingham Green" are all startlingly accurate send-ups of prog-rock, and they are better written than many of their inspirations.

Similarly, the vulgar shanty "The Blarney Stone," the faux-Richard Thompson tragedy "She Wanted to Leave," and the sunny, Caribbean-flavored "Ocean Man" are terrific songs offering evidence that Ween are improving as songwriters and musicians with each record.

Ironically, this array of silly jokes and musical parody is a richer and more diverse listen than most of its alternative rock contemporaries.