Comments:

I recorded this Cowbird (wave533) while it was sitting calmly on a telephone pole.  The cadence of this song reminds me of the cardinals "whir-a-chee", just a little faster, and much higher in pitch.  There is a quality to this sound that reminds me of electricity fired off of electric train wires or a sneaker twisting on a basketball court..  I have also seen this bird at the feeders in the Great Swamp.

Stokes describes the song of the brown-headed cowbird as "bublucomsee"; call is high "pseeeseee" and "ch'ch'ch'ch."  The bird I saw did not sound anything like this.

Robbins describes this sound as a thin "whistle".

Peterson describes this bird as follows:  Note:  "chuck". Flight note:  "weee-titi" (a high whistle followed by two lower notes).  Courtship song, bubbly and creaky, "glug-glug-gleee"(last note thin on high pitch).

Related links:

"Stealth, Lies and Cowbirds", http://www.blarg.net/~critter/AvianFamily/cowbird_1.htm, by S. Milius, Science News Magazine. Short academic bibliography.

Lisa, Petit, "Brown-Headed Cowbirds:  from Buffalo Birds to Modern Scourge,"  Smithsonian Migratory Bird Center, http://www.si.edu/smbc/fxshts/fxsht3.htm.  Bibliography.