Chicago 17 was a peak for the '80s incarnation of Chicago, the ideal blend of Peter Cetera's adult-pop craft and David Foster's slick yet lush production, an album that spawned four huge singles and went platinum six times, turning it into their biggest hit ever.

There was nowhere to go but down but there was little indication how far Chicago 18 would take them.

Cetera decided that the blockbuster success of Chicago 17 would be a perfect launching pad for a solo career, so he bolted prior to the recording of 18 -- but the band didn't pause, hiring Jason Scheff as his replacement and retaining Foster as producer in the hopes of replicating the success of its predecessor.

Certainly, Chicago 18 is within the vein of 17 but there are some crucial differences, all stemming from the departure of Cetera.

Without him, a certain warmth is missing, both in the writing and in the sound, as all the smooth soft sounds turn into something strident and slick.

Foster's production relies too heavily on stiff synthesized sounds and boomy echoes; everything is pushed to the front, so it's not easy to sink into the production, the way it was on 17.

This, along with a severe drought in good new songs -- only the by-committee power ballad "Will You Still Love Me?" works in this context (the other hit single, "If She Would Have Been Faithful...," has just too weird a conceit to work) -- is a greater detriment than the utterly anonymous Scheff, who performs his role as the stand-in Cetera ably.

He slips into the allotted spaces in Foster's production, never standing out from the wall of sound -- and neither does Chicago as a band, either, even if they try so mightily to assert their identity that they revive "25 or 6 to 4," a misguided move that only reveals that they're not in control here, Foster is.