* * * * <i> Great Balls of Fire</i> * * * <i> Good Vibrations</i> * * <i> Maybe Baby</i> * <i> Running on Empty : </i> : WHAT’S THE RUSH?

* * 1/2 “HOLD YOUR FIRE.” Rush. Mercury. With wildly uneven recoded product since 1982, this Canadian pomp-rock trio has been riding one helluva roller-coaster the past few years. The power and the glory of the band’s instrumental assault remain fully exposed in Rush’s latest opus, “Hold Your Fire”--mostly thanks to Peter Collins’ co-production efforts--but some of the band’s more annoying traits are creeping back into the mix.

Oh, those lyrics! As a wordsmith, Neil Peart remains a terrific drummer; the ponderous images and the ought-to-be-illegal rhyme schemes continue to confound singer Geddy Lee’s tenor bullfrogging, in spite of his new-found relaxed phrasing. And oh, those orchestrations! On “Power Windows,” Collins’ tasteful addition of strings, brass and choirs added a little flavor to the brew without going overboard. Here, Lee’s synth flourishes wash a lot of power away, while the acoustic instruments get buried under the digital tides.

At the same time, Lee is singing (and playing bass) with enjoyment and authority, guitarist Alex Lifeson is expanding his immense tonal vocabulary even further, and Peart continues to amaze behind the kit. In sum: a small step backward, but no great leap for Rush’s kind.