During a lunch time walk today here in Harford County I heard a similar "PEET-
SEET" call I thought could possilbly be an Acadian, BUT knew it wasn't.  I've 
never heard much variability in the classic "PEET-SUP" or pizza call (strong, 
travels well).  The notes and tone I heard on this "PEET-SEET" were similar to 
Acadian, but the message was all wrong.  What was around were YELLOW-
RUMPED WARBLERS and there variable warbles and cadences.  The variability 
of "sounds" coming from these Yellow-rumps were all over the board.  From 
strong repetitive PEET-SEET calls to soft, melodious warbles.  I found 
my "PEET-SEET" call(s) coming from one or two individuals which started their 
song (or calls) low and warbled and then ended with the stonger "PEET-SEET".
Given the songs or ending call notes had travelled a little ways through the 
forest, when I first heard them my ear heard "possible Acadian?", but the brain 
said no way on these guys.

I not saying this means anything nor do I mean to suggest this as some expert 
commentary, just thought the sounds and observations were or may have 
been similar and wanted to share.

Keep sending those birds northward,

Rick Cheicante
Harford County
Bel Air, MD