Concord, Mass.
1907
April 3
(No 3)
  The immense numbers of Juncos seen to-day gave me
an exceptional opportunity to study and compare the songs
of many different individuals. I must have heard more
than one hundred different birds. Many (the majority I think)
sang more or less like Pine Warblers for which, indeed, I
mistook several of them for an instant and one bird until
I got very near and heard him several times. Others
reminded me most of Chippies but these, without exception,
put more of life and melody into their notes than the
chippy ever does with his dry, listless song. Others again
(there were but three or four in this class) sang very 
like Myrtle Warblers. The song of one bird was so
closely like that of the Swamp Sparrow that I was
completely deceived until I actually saw the bird in
the act of producing it.
Variations in the songs of Juncos
  Thus far I have been referring exclusively to the song
trill which the Junco uses on its breeding grounds. The
medley singing, peculiar, I believe, to early spring, was 
frequently heard to-day. I noted the following rendering
of it after listening carefully to a bird for some time.
Quip-quip-quip-quee-e-e-e-quil-l-l-l-l-l (ie the
normal trill interpolated here beginning with "quib"). Cheep - cheep
(the normal call note) quip-quip-quip-quee-e-e-e
quil-l-l-l-l-l etc. This was repeated many times
at short intervals always in low, subdued tones.
Some of the notes were very musical and the general
effect of the performance was very pleasing. I wonder 
if it can represent the first (or early) attempts
at singing on the part of young birds. It can
hardly be termed sotto voce singing (it is too loud for
that). Rather I should call it a musical soliloquy.
Medley singing of the Junco.