[mou] Sparrow ID Help - Please!

[Pastor Al Schirmacher]

While doing a big day in central MN yesterday (120 species in Sherburne, 
Mille Lacs & Aitkin Counties - while missing some "bunnies") - a sparrow 
popped up that baffles me a bit.  Observations follow:

* Relatively thin black eye line that proceeded to but not through the eye
* Relatively thick white chin line
* Dark upper breast - initially reminded me of a Harris' upper chest, then 
realized that the area was full of dark lines, not solid color
* Larger body, well within the normal brown colors of an average sparrow
* Song:  clear, six+ notes - not insect-like or buzzy at all - not 
particularly rolling or bubbly either - bird threw back it's head from 
branches of a dead tree about 15 feet high and let loose like a Song 
Sparrow - song was unlike any sparrow's I've heard before - I'm  conversant 
with the normal upper Midwest sparrow songs, but not in the western or 
plains states varieties
* Location:  open field next to a small farm, boreal woods across the road - 
area known for unusual species - north central MN (for those who know the 
state, "Pietz Road" just off of CR 18 in Aitkin County, near the area BB 
Magpies & GG Owls are sometimes seen)

Closest illustration I could find is Sibley's female Lark Bunting - some of 
the unusual Savannahs are close, except the song was dramatically 
different - opinions and thoughts?

Thanks!

Al Schirmacher
Princeton, MN
Mille Lacs & Sherburne Counties