With Seis de Mayo, Trey Anastasio returns to the willful musical obscurism that marked his ventures outside of Phish prior to his major-label unveiling as a solo artist, 2002's Trey Anastasio.

That record was a delightful surprise since it was both eclectic and polished, featuring the singer/guitarist at his most tuneful and adventurous; arguably, it was better than any Phish album, and it certainly was useful in converting doubters.

While 2004's Seis de Mayo isn't as obviously patchwork as One Man's Trash -- whose very title suggests its contents -- it is pieced together from sessions held between 2000 and 2003 and consists largely of reinterpretations of familiar Anastasio instrumental compositions, most now reworked to feature some sort of classical arrangement, ranging from string quartet to a full 66-piece orchestra on the nearly 12-minute closer, "Guyute (Orchestral)." Since Phish have a reputation as an improvistory band, some skeptics might think that their songs aren't so much composed as discovered, but close listening to Anastasio's work reveals that's not the case.

Ironically, Trey Anastasio made a stronger case for his work as a composer than Seis de Mayo because it cast a wider net and accomplished more on its own terms.

Seis de Mayo is disjointed and diffuse, sounding like an idea sketchbook through its first half before it moves to some very interesting work on the last three tracks, which aren't coincidentally pieces that he wrote with orchestras in mind.

They all reveal considerable skill at writing for larger ensembles -- the arrangements are dense and lively, but not overly busy, pushing at dissonance without delving into noise, boasting some muscular themes and countermelodies -- and they're all worthwhile listening.

It's not quite enough to make Seis de Mayo successful -- that first half doesn't work particularly well, and while the latter half is interesting, it's not necessarily absorbing -- but it is an admirable experiment that points toward bigger, possibly better, things.