n essential factor in
the fully developed three-part form--it seems better to consider this
piece, and others like it, as a tendency rather than as a complete
embodiment of tripartite arrangement. It is expected that the music
lover will take these Inventions for what they really are and not
search in them for those notes of intense subjectivity and dramatic
power so prevalent in modern music. They are merely little pieces--a
"tour de force" in polyphonic ingenuity; music rejoicing in its own
inherent vitality. Accepted in this spirit they are invigorating and
charming.

The form in which polyphonic skill reaches its highest possibilities
is the Fugue; and the immortal examples of this form are the Fugues of
John Sebastian Bach, found in his _Well-tempered Clavichord_ and in
his mighty works for the organ. The fundamental structure of a fugue
is implied in the term itself (from the Latin "fuga"--flight); that
is, in a fugue the main theme or subject is always announced in a
single voice, and the remaining voices, appearing successively in
accordance with definite principles of key-relationship, seem to chase
each other about and to flee from pursuit. The several stratified
entrances of the subject are relieved by intermediate passages called
"Episodes." An Episode, as shown by the derivation ([Greek: ipi
hodos], by the way), is something off the beaten path--a digression;
and it is in these episodical portions of a fugue rather than in the
formalistic portions that the genius of the composer shines forth.
This is especially true of Bach, for almost any well-trained musician
can invent a subject which will allow of satisfactory fugal treatment
according to accepted usage; but no one save Bach has ever invented
such free and fanciful episodes--so daring in scope and yet so closely
connected with the main thought. The general effect of a fugue is
_cumulative_: a massing and piling up of voices that lead to a
carefully designed conclusion which, in some of Bach's organ fugues,
is positively overwhelming. A fugue may be called a mighty crescendo,
like the sound of many waters. There is a popular conception, or
rather _mis_conception, that a fugue is a labored, dull or even "dry"
form of composition, meant only as an exhibition of pedantic skill,
and quite beyond the reach of ordinary musical appreciation. Nothing
is farther from the truth, as a slight examination of musical
literature will show. For we see that the fugal fo