Of the trends and affectations that began to emerge in the indie rock scene of the past decade, the one that always inspired admiration and confusion in me was that bands suddenly started having two drummers. The sight of two drum kits on a stage tends to be a compelling one, but what I started noticing was that there was rarely a need for two drummers to participate. By and large, they would play the exact same rhythms, which I suppose one could argue would make for a fuller sound, but the impression usually was that having two drums was more a stunt than anything really practical.

To be sure, there are a number of exceptions to this observation: Radiohead's descent into repetitive bleeps and bloops was partially salvaged, for me, by the complex polyrhythms of their dual drummers, and there are scads of prog-rock bands whose compositions would only be performable with the aid of a second drummer. It is only through the experience of seeing double drumming done right that I was suddenly aware of how unnecessary it is much of the time. That experience came from seeing Gems perform at the New Frontier a few years ago.

Hailing from Seattle, Gems is an electro-rock band consisting of two guys on keyboards (Gary Palmer and Dan Rapport), and two guys on drums (Adrian Van Batenburg and Jacob Evans). Set up so that the drummers are facing one another, a Gems live set is a mesmerizing thing to behold, with the two percussionists' interplay creating a visually striking bit of theater that compensates for the comparatively static tableau of the keyboardists. This is a situation where having two drum kits is an essential, defining quality of the band - one drummer will hold down the beat while other lends syncopated flourishes, and then they'll switch, weaving in and out of each others' patterns, creating a shifting floor on which to rest the melody of the synths.

While the drums provide the most immediately engaging visual element, Gems is a band where the four musicians are completely cooperative, creating songs that are more than the sum of their parts. Even as someone who usually finds instrumental songs to be not particularly involving, I was won over by Gems' inventive arrangements that continually introduce hooks and pockets of fascination. This is electronica that skirts the sanitized vibe that can sometimes hamper the genre, instead embracing a tactile feel that digs its claws into the listener and inspires movement from the most introverted of audience members.

For someone like me, who has never had the patience or dexterity to learn playing an instrument, seeing a live band wow a crowd can sometimes have the same effect as seeing a magic trick. Witnessing talented individuals making art with foreign objects can invigorate you; having conquered the ability to make music, it's impressive that anyone would go on to make great songs. I think this gets to the heart of why double drumming started running wild over indie bands: it generates intrinsic interest and drama in a time when bands aren't quite so into theatricality. Seeing Gems, that feeling of awe and investment came flooding back, like watching two guys doing a more intricate, toe-tapping version of spinning plates. The synths that accompany the drums enable Gems to be just as enjoyable on record, but their live show is something to behold.

Friday finds Gems performing at the Valley, which has an intimately tiny stage. I predict that this should serve well as a setting to draw you deeper into their hypnotic electronica.

Gems, w/ Pacific Sunrise Quartet, Retrospecter, 9 p.m., Friday, Dec. 2, Cover TBA, The Valley, 1206 Puyallup Ave., Tacoma, 253.248.4265