1) Songs of the songbirds are generally divided into two or three parts. A prefix (an introductory note or notes), a root (middle song, usually a trill or warble) and a suffix (an ending).

2) Diagnostic Prefixes

The song of the Northern Oriole begins with a one or two note introductory prefix.  Often, the Prefix is sung by itself.  The prefix varies from bird to bird. 

The song of the White-eyed Vireo begins and ends with a very loud "chit" sound. 

The Canada Warbler also begins his song with a diagnostic "chit" note.

3)  Does the song ascend or descend in pitch?

The chattering trill of the Wilson's Warbler drops in pitch. 

4)  Diagnostic suffixes.

    Blackburnian Warbler

    White-eyed Vireo

5) Birds whose song consists of only a trill:

    Chipping Sparrow

    Pine Warbler ??? (or is each note separated by a barely audible pause?)

6) Birds whose song begins with a trill (no suffix):

Yellow-rumped Warbler.  The suffix can be either gradually descending (Slide Mountain)(Delaware Water Gap) or a two part song alternating with a descending ending followed by a sequence with an ending with a single high note. (Yosemite)

7)  Warblers

Most have song variants that rise in pitch or descend in pitch. Chestnut-sided Warbler, Yellow-rumped Warbler;

Many have a prefix of a series of ____ to 5 notes or a fast trill that sounds like one note followed by either an ascending or descending suffix.  Chestnut-sided warbler; Redstart.