I need help from all of you with experienced ears.  I heard this bird
yesterday morning and am unconvinced of the ID.  A brief recording of its
song is here (I have a couple of minutes with it singing repeatedly, but
figure a short clip would suffice?):

http://www.cs.umd.edu/~farrell/UNK_5May08.wma

I'm eager to hear any and all thoughts on it.  I wasn't able to see the
bird, but it was up in the canopy alongside a creek (on the Paint Branch
Trail not far from the University of Maryland).

Many thanks in advance,
Ryan Farrell,
College Park