Think of Rick Rubin, the ZZ Top-bearded record company mogul and producer-to-the-stars, as the music business' very own Dr. Frankenstein.

Like the doctor, Rubin has demonstrated a predilection for patching together musical monsters by culling ingredients that he's found lying around. Aided by his eclectic tastes, a deep understanding of pop music history and perhaps a dash of the perverse, Rubin's fame as a producer extends not from the sonic quality of his production work, but the unorthodox ideas that he's come up with. After all, he's credited with bringing Run DMC and Aerosmith together in the mid-'80s for "Walk This Way," a combination that gave hip-hop its first major MTV crossover. (Most recently, he thrust modern rock chestnuts like Nine Inch Nails' "Hurt" and Depeche Mode's "Personal Jesus" into the hands of Johnny Cash for the country legend's newest release.)

Rubin's latest handiwork is Audioslave, an old-school hard rock band that combines the three instrumentalist of leftist rap-rockers Rage Against The Machine with former Soundgarden singer Chris Cornell.

It seems that the producer already had a plan in mind for the band's future shortly after Rage vocalist Zack de la Rocha quit the band in October 2000 with the completion of its overlooked covers album "Renegades," which Rubin rode shotgun on. Subsequently bestowed with a consigliore position by the remaining members of the group -- guitarist Tom Morello, bassist Tim Commerford, and drummer Brad Wilk -- Rubin hatched the idea to remake the band into a 21st Century version of Led Zeppelin.

Even before a new vocalist was officially on board, Rubin was broaching the idea, hinting to Rolling Stone magazine in late 2000 that he thought this "could turn into a Yardbirds-into-Led Zeppelin scenario."

"In many ways, Tom Morello is the Jimmy Page of today," Rubin told the magazine.

Hyperbole aside, Rubin suggested the trio invite Cornell to jam. The selection of Cornell was ideal for all involved. He offered the band a seasoned frontman with the kind of trademark pipes that could compare to Robert Plant, a moody, aloof onstage charisma that contrasts sharply with de la Rocha's ferocity, and impressive songwriting abilities (best displayed on Soundgarden's "Superunknown," a true heavy rock masterpiece).

For Cornell, the union couldn't have come at a better time. After disbanding Soundgarden in 1997 because of creative tension, Cornell tried to reinvent himself as a singer-songwriter eerily reminiscent of his old buddy Jeff Buckley. However, his solo record, 1999's "Euphoria Morning," was maudlin and stilted.

This new endeavor offered the singer not only an escape from solo artist purgatory, but presented some intriguing challenges. While Cornell often resorted to wailing his guts out in order to be heard over Soundgarden's thunderous guitar onslaught, teaming up with the ex-Rage members would give him the chance to interact with one of rock's nimbler rhythm sections.

And while the band members have been talking up the group's initial creative chemistry in interviews -- citing the fact that their self-titled debut was drawn from the 21 songs that they came up with over 19 days -- there still a few questions that need answering. Chiefly, what else has Audioslave been doing for the past two years and is this really the best that they could come up with?

Admittedly, there's a few songs on "Audioslave" -- the hardest hitting ones -- that live up to Rubin's hopes. It can't be anything but thrilling to hear a song like "Cochise" come blaring out of a radio. While the band lays down a sinister groove, Cornell howls like he's swept up in the hard rock exhilaration. Equally volatile, "Set It Off" comes the closest to sounding like a political anthem, but its point is obscured by the vagueness of the lyrics and ultimately, the frenzy in Cornell's voice and Morello's punishing riffs.

"Show Me How To Live" is nearly identical to the rough demo version of the track that was leaked on the Internet last spring when the group was still calling itself Civilian, but by the time the band dives into the chorus, the song erupts with a new blast of energy. Cornell's voice soars, weaving through a rotating storm of raucous guitar and grumbling bass.

For the Rage guys, a song like "Shadow Of The Sun" can be hailed as a personal breakthrough. The track, which is probably a candidate for the group's second single, has the group focusing on playing melodically and with remarkable control. Although the chorus features the obligatory loud riffs, the trio shows a softer side that previously would have been unthinkable given Rage's strict musical formula. Morello in particular, renown for his heretical attack on the guitar, plays a restrained solo with the notes slowly percolating forth before swirling into what sounds like two supercomputers locked in a death match.

Unfortunately, the majority of mid-tempo cuts on "Audioslave" turn out to be real duds. While the record has a lot of similar-sounding heavy songs that could have been cribbed from any of Rage's old albums, "Like A Stone," "Getaway Car" and "I Am The Highway" appear to have Cornell's fingerprints all over them. The preponderance of Cornell's undynamic singing and the vanilla melodies suggest that these cuts could be remnants from Cornell's "Euphoria Morning" period hoisted on his unsuspecting bandmates. The worst of these, "I Am The Highway," has Cornell passionately singing the most jejune lyrics, "I am not your autumn moon/ I am the night."

Contrary to Rubin's grand scheme, "Audioslave" is not "Led Zeppelin I." Rather than a unified whole, their music -- to twist a phrase that Morello himself has used -- is like two great tastes that occassionally taste great together.

But just like the albino children that are climbing the mystical pyramid on the cover of Zeppelin's "Houses Of The Holy," Audioslave is still in the process of crawling towards the light.

• Audislave's Official Web Site
• Rage Against The Machine's Official Web Site
• Chris Cornell's Official Site
• A Gathering Of Slaves (Unofficial Site)
• Audioslave Online (Unofficial)
• Audioslave (Unofficial)

• Past Columns