Edgard Varèse: "Ionisation"
Although not necessarily a piece for wind band, Edgard Varèse's Ionisation has been performed on too many wind ensemble concerts and is too important a piece to not be mentioned in a blog dealing with wind music. If you are interested in background on Varèse, please look through previous posts on the composer.
Widely regarded as the first piece written for "percussion ensemble", Varèse wrote Ionisation in 1929-1931 after most of his works for winds had already been composed. You can find extensive information and a performance of the piece below.
"Ionisation" program notes from the Chicago Symphony Orchestra
Wikipedia article on "Ionisation"
Background information on "Ionisation"
Edgard Varèse, Ionisation
Ensemble InterContemporain, Pierre Boulez, conductor