When a rock band loses two of its members and is dropped by a major record label, chances are its days are numbered. With alt.country turned avant-rockers Wilco, these rules don’t seem to apply. With the release of the critically fawned over Yankee Hotel Foxtrot last April, Wilco is enjoying its most commercially successful year yet. Founded by chief songwriter and guitarist Jeff Tweedy and bassist John Stirratt in 1994, Wilco descended from the seminal country punk band Un...