Madison band Cougar performed a textbook example of a good underground show at the Orpheum Stage Door Tuesday night. With absolutely no advertising besides word-of-mouth, the band packed the hole-in-the-wall theatre behind the main Orpheum entrance.

Even at the door, there was no mention of Cougar besides for the fliers for upcoming shows. This sense of mystery was Cougar's main asset, undertaken with the same quiet intensity that characterizes the band's music.

The brief but breathtaking show revealed the instrumental sound of Cougar's full-length debut, Law, to a live audience for the first time. In the space of an hour, the five-piece group played a set of densely structured songs that jumped from lilting neo-classical melodies to heavy dance beats to blistering rock choruses with astounding precision.

Each song was based on ornate, dreamy guitar melodies repeated with mantra-like intensity. Guitarists Dan Venne and Trent Johnson began the compositions with flowing mini-overtures that gradually built into full-on sonic attacks.

But while the melodies were impeccably constructed, it took Dave Skogen's unconventional beats to make the band's atmospheric moodiness come alive. Skogen's playing went from abstract washes of cymbals to syncopated grooves to full-on whaling beats with startling frequency. The rhythm section shifted from drum 'n' bass beats to Latin grooves seamlessly.

Skogen even drew on synthesized sounds, triggering an electronic backbeat with one hand during the climax of "Pulse Conditioner."

He was aided in this experimental aspect of Cougar's sound by recorded ambient noise. Unfortunately, these sounds seemed more like background noise than a well-incorporated part of the music.

The ambient noise aspect was more successful between songs, where recorded sounds were used to buy the guitar players time to switch instruments and tune up. The fascinating interludes kept up the show's momentum, even when the acoustic guitars could be heard tuning in the background.

Technical glitches like these could easily have thrown the show off track, but impressively, they didn't. The band quickly recovered from small mistakes like a guitar strap falling off and unexpected delays while switching instruments.

They couldn't do anything about the sound mixing, however, which eventually achieved an uneasy balance between the loud bass and drums and the delicate guitar tones. At first, the drums overpowered everything else during the louder sections, prompting the sound tech to turn them down. This resulted in a better mix but inevitably delivered less clarity. Amplified, the acoustic guitars sounded too much like their electric counterparts, losing a lot of their shimmering tone.

The images projected onto the large backdrop behind the stage worked almost flawlessly, dissolving into a blank computer screen only once. These colorful backgrounds included rolling fields, blue skies and pumpkin innards, all interspersed with album art and images from the band's website, www.cougarsound.com. The images melded perfectly with the music, as did the flowers along the front of the stage.

Despite technical glitches, Cougar kept the audience on the edge of their seats through long sections of mellow sounds. Instead of trying to drown out the chattering audience, the band began the show with the quiet cymbal textures of "Atlatl," and the audience soon shut up. Throughout the rest of the concert, they eliminated the bar-band atmosphere that is often a danger at small shows.

Cougar was in no rush to rock out, preferring to make the audience wait in anticipation. Their patience was rewarded with short, majestic sections of soaring space-rock in the spirit of Godspeed You! Black Emperor. "Atlatl" came to such a roaring finish with a beautifully orchestrated harmony of overdriven guitars. "Your Excellency" also quietly persisted before coming to a jolting rock climax.

The audience rose to give a standing ovation as Cougar left the stage, summoning them back on for an encore of Radiohead's "Optimistic." Jubilant crowd members provided the vocals for the band's instrumental take on the tune, singing loudly from the aisles.

Although Cougar's inexperience was occasionally evident in technical difficulties and transitions between song sections, the show was a stunning debut for the Madison band. Cougar has since left for a two-week European tour, even though they'd be welcomed back in an instant for more local shows.

Keep your ears open and you just might hear about the next time Cougar plays Madison, though there are no guarantees.