Just putting together some comments on the "fuging tune" [Example], a song type of British origin and popularized by the "First New England school". The "First New England School" includes American musicians such as William Billings, Supply Belcher, Daniel Read, Oliver Holden, and Justin Morgan (most of whom lived from the mid-1700s to the early-1800s). These writers developed a musical style largely independent of European models. Because of this, the "First New England School" is usually considered the first uniquely American music.
Most scholars agree that the term fuging tune is a shortened form of the English phrase "fuging psalm tune".
"Fuging tune: A tune upon which a fugue is built." -- Virginia Tech Multimedia Music Dictionary
In The American Fuging Tune: 'Marks of Distinction', Maxine Fawcett-Yeske describes fuging tunes as "three- or four-part polyphonic choral settings of metered sacred texts" and notes that "Imitation, sequence, and the rudimentary spinning-out of musical motives are procedures present in the early British models that find their way to varying degrees into the American repertory."
In American Fuging Tunes in The Sacred Harp, Molly Cronin describes the common form: "The fuging tune as we know it today is a binary form with a homophonic, homorhythmic A section, followed by a repeated polyphonic B section, often using points of imitation. The earliest fuging tunes had these contrapuntal sections simply as optional extensions of the homophonic section."
"fuging tune, a form of hymnody developed by American composers of the so-called First New England school during the period of the American Revolution (1775–83).
"A typical fuging tune places the tune in the tenor voice and harmonizes it with block chords. In the next-to-last phrase, called the fuging section or fuge, each of the four voices enters in turn singing the tune or a slightly varied version of it. The last phrase is again chordal. The fuge, although all four parts follow each other in melodic imitation, is not a classical fugue but merely a passage that uses imitative writing."
"fuging tune." -- Encyclopædia Britannica Online. Encyclopædia Britannica, 2011. Web. 21 Jan. 2011.
Karl Kroeger’s definition of fuging tune is one which "contains at least one section in which the voices sing different words simultaneously." (American Fuging Tunes, 1770-1820, 1994.)
"A shape-note fuging tune has one or more sections with staggered entrances; the various parts begin the fuge in different measures, rest, enter again, and sing over each other, indeed making the music soar." -- Malinda Snow, Georgia State University in "The Sacred Harp" in The New Georgia Encyclopedia
George Pullen Jackson provides more of a description than a definition the fuging tune in White Spirituals in the Southern Uplands, as follows:
"In the fuging tune all the parts start together and proceed in rhythmic and harmonic unity usually for the space of four measures or one musical sentence. The end of this sentence marks a cessation, a complete melodic close. During the next four measures the four parts set in, one at a time and one measure apart. First the basses take the lead for a phrase a measure long, and as they retire on the second measure to their own proper bass part, the [tenors] take the lead with a sequence that is imitative of, if not identical with, that sung by the basses. The tenors in turn give way to the altos, and they to the trebles, all four parts doing the same passage (though at different pitches) in imitation of the [part in the] preceding measure. ... Following this fuguing passage comes a four-measure phrase, with all the parts rhythmically neck and neck, and this closes the piece; though the last eight measures are often repeated."
Not everybody liked them:
"Instead of those plain and easy Compositions...away they get off, one after another, in a light airy jiggish Tune....The matter of the Psalm has very little Share in their Attention." -- From a 1764 letter to a Boston newspaper, quoted in Church Music in America, 1620 to 2000, by John Ogasapian, p. 34