''This is perfect,'' Tweedy said, surveying the stately surroundings of the Pritzker Pavilion on a cool, clear and beautiful evening.
Throughout the night, an exquisite sound mix captured the most subtle moments in the most fragile songs (say, the first third of ''I Am Trying to Break Your Heart'') as effectively as the ferocious, full-throttle rock explosions (such as the one at the climax of ''Handshake Drugs'').
Best of all were the tunes that embraced both dynamic extremes, including many from the new album -- two of the biggest highlights here were ''Side with the Seeds'' and ''Impossible Germany'' -- as well as fan favorite ''Via Chicago,'' which prompted a sing-along stretching from the stage lip to back of the lawn.
When released last spring, ''Sky Blue Sky'' came as a bit of a disappointment: The predominance of quiet, lulling to downright sleepy material was a letdown after the fiery live shows during the endless touring behind ''A Ghost Is Born'' (2005), which found the current lineup of Tweedy, veteran bassist John Stirratt, drummer Glenn Kotche, guitarist Nels Cline, keyboardist Mikael Jorgensen and guitarist-keyboardist Pat Sansone solidifying as the strongest the ever-evolving group has had.
Onstage Wednesday, almost all the live versions of the new songs trumped the recorded renditions, thanks to the intensified dynamics and fluid interplay of this accomplished ensemble. The sole exception was the Little Feat homage ''Walken,'' a clunker nothing could save. Nor could anything justify the band selling a half-dozen of these songs to a series of unremarkable car ads -- but that's a whole other critique.
Perfect? In the end, Wilco may not have been as sublime as the weather, the venue and the sound. But it came pretty darn close.