The supergroup. What a horribly dated concept that is. It smacks of corporate rock and overinflated, believe-your-own-hype egos, as in, "Hey man, you're the coolest guy in your group, and he's the main man in his band, and without me, my band is nothing, so like, if the three of us get together, man, it'll be an incredible band."

Maybe. Such thinking sometimes leads to artistic wonderfulness, as in Cream or (arguably) the Traveling Wilburys, and sometimes not, as exemplified by the ill-fated Blind Faith, where the whole was definitely less than the sum of the individual parts.

The supergroup concept has never really caught on here in Japan, which in many ways is a good thing. Tsunku, the Svengali behind Morning Musume, has been spinning off members of his stable of female "talents" into various new groups, of course, but these hardly qualify as supergroups -- the individual members of Morning Musume are so many peas in a pod, replaceable at a moment's notice with any one of the myriad musume out there.

The only supergroup worthy of the name in Japanese pop history is Yellow Magic Orchestra, the pioneering electro-pop trio comprising Ryuichi Sakamoto, Haruomi Hosono and Yukihiro Takahashi, each of whom had achieved fame in other bands before forming YMO. You might argue that Motoharu Sano's Hobo King Band was another supergroup, but the label somehow doesn't really fit that rather low-key ensemble.

But the formation of Ajico last year shows that there's hope for the supergroup concept in Japan. The band got started when Kenichi Asai, vocalist-guitarist with Kansai rock trio Blankey Jet City, suggested to UA that they form a new band. BJC broke up at the end of last year, after a very successful 10 years as one of Japan's leading rock bands, apparently due in large part to Asai's desire to do something different musically.

I can understand his thinking, since BJC had pretty well played itself out as a creative force. He and UA had already worked together; he wrote the beautiful ballad "Strawberry Time" for her, and UA's performance of the song on her most recent studio album, 1999's "Turbo," is simply exquisite. Having set that very high creative benchmark for themselves, Asai and UA then recruited Tokie, bassist with popular new rock-rap trio Rize, and drummer Kyoichi Shino, who had also previously worked with UA.

On paper, Ajico looked like a very promising unit, but so have many other supergroups, which have then gone on to make uninspiring music. Ajico lived up to its potential, however, with the release in February of "Fukamidori (Deep Green)," which is definitely in my list of top 10 albums for 2001. Freed from the stylistic straitjacket of BJC, Asai stretched out both as a writer and a guitarist, leading the band in several improvisational bits that give full vent to the musicians' desire to go beyond the conventional pop-song format.

UA, as the band's main vocalist, showed once again why she is one of Japan's most intriguing artists. Her singing is somehow simultaneously earthy and ethereal.

The only thing that spoiled "Fukamidori" is Asai's singing. He is a very talented songwriter and guitarist, but unfortunately he belongs to the strangled-ferret school of Japanese male rock vocalists. Ouch, already.

Ajico has achieved a solid reputation as a live band, so it makes sense that their latest release is a single comprising two live tracks: "Pepin," which Asai wrote back in his BJC days, and "Sunny," a long-ago AM radio hit for one Bobby Hebb. Putting out two live tracks as a single is very unusual, especially in the J-pop world, but it's typical of Ajico's unorthodox way of doing things.

"Pepin" is a punchy, powerful track, with the Tokie/Shino rhythm section in powerful form, Asai playing funky, incendiary guitar and UA in her best belter mode. An inspired choice as a single release.

"Sunny," the B-side of "Pepin," highlights UA's weakest point: her English-singing ability. As she showed on the live album "Fine Feathers Make Fine Birds" a few years back, UA's English pronunciation simply doesn't make it: "Sunny" comes out as "Thunny," for example. Just why UA insists on these English excursions is a mystery to me: Stick to Japanese, UA, please.

That said, Ajico's version of "Sunny" has a dark undertone only hinted at in the original. Tokie's fretless bass gives the song a sexy, sinuous quality, and Asai's guitar sounds vaguely Middle Eastern.

It's not clear whether Ajico is a long-term project or just an interesting side project for those involved. UA has her own career as a solo singer-songwriter and now movie actress; she's landed the starring role in director Hidenori Sugimori's film "Mizu no Onna (Woman of Water)," which commences filming this fall and is set for release next summer. It's hard to see her committing herself to Ajico over a long period.

Asai is also busy with another band, the Sherbets; Tokie has Rize, while Shino is something of an unknown quantity.

Anyway, I'm eagerly awaiting "Ajico Show," Ajico's live album, which is due out July 25. I just hope Asai's vocal contributions are kept to a minimum.