The Op. 30 Postlude in A Major is a stand alone 4-voice fugue written in quadruple counterpoint with 3 countersubjects maintained throughout (photo).
In this work the subject begins boldly on the mediant note and has a tail which points strongly to the dominant key, thus a real answer in the dominant is supplied; the tail of this subject also has a trill on the final note which is realized with notes having precisely specified time values; the upper auxiliary note of this trill is also tied to the preceding note.
Here, in accordance with the general practice of Contemporary music writing (c. 1900 -- present), the trill was not symbolized with a pictograph but written into the notation as ordinary notes and is omitted when the subject enters in the bass, since the pedal is not concerned with it.
When the note which is otherwise trilled enters in the bass the duration of the preceding note (which would have been tied to the upper auxiliary note of the trill) is lengthened by a unit of value (the most common note appearing in the composition -- in this case, an 8th note) to compensate for the missing trill and to avoid creating a disturbance in the rhythm.
In this densely contrapuntal work it was the composer's intention to realize this trill in accordance with Baroque performance practice which specifies at least 2 repercussions when a note is trilled (each upper appoggiatura, or auxiliary note, in a trill is called a "repercussion").
But here, since the trilled note is preceded by the previous upper 2nd in the subject's melodic outline, the trill necessarily starts on the note itself, i.e., the main note.
NOTE: This is an important point which has not always been given sufficient emphasis; the rule is, all ordinary trills in Baroque music start on the beat with the upper auxiliary note, thus providing a minimum of 2 repercussions in the realization -- BUT NOT ALWAYS, not 100 per cent of the time; when the main note of the trill is immediately preceded in the same voice by the upper auxiliary note, the dissonant note of the trill has already exerted itself, and the trill will start on the main note instead; also, in fast tempos where the trilled note is of short duration, the trill may have to start on the main note either to 1) maintain tempo or 2) avoid blurring the melodic or harmonic line, either of which would be sacrificed if, in such cases, the rule were strictly followed; it would in fact be justifiable practice to realize trills this way not only in the music of Bach and his school but with any new music having the same kind of independent voice leading and dense contrapuntal texture, however most musical ornaments have become obsolete today and are seldom, if ever, notated in the score as in former centuries -- contemporary composers simply write explicitly in ordinary notation the notes in the score which they wish to have played to indicate the trill's intended execution.
Returning to the Op. 30 Postlude, the entries proceed through all nearly related keys plus one unrelated key (G Major), and the subject and 3 countersubjects each take turns entering in the bass in the same chronological order as they do in the opening exposition.
In the episodes separating the entries the outer voices (soprano and bass) are silent as the inner voices (alto and tenor) carry the music forward; these episodes are all of uniform length and constructed using fragments of the subject, countersubjects, their inversions, or by means of sequences.
The final entry in the home key, following many examples left to us by J.S. Bach, places the subject in the bottom octave of the pedals.
A short coda rounds out the piece during which an additional voice (low tenor, or baritone) enters on the middle staff.
This music ends in 9 voices on a big tonic chord with a held 2nd and double pedal.
The trill in the tail of this fugue's subject is a type of ornament, just one of many such embellishments or sets of auxiliary notes composers have associated with a main note, evidence for which extends all the way back to the 14th century; ornaments make music more expressive by using these auxiliary noes to create a dissonant sound which resolves to the consonant sound of the main note, thus creating a sense of tension and release.
Ornaments are typically written into musical notation either as an auxiliary note in small print ahead of the main note, as a special sign over the main note, or as a series of additional notes in small print; these embellishments are like salt and pepper -- they add some seasoning to the musical recipe, and, as such, need to be inserted wisely and sparingly; too much of this salt and pepper can ruin a piece just like it will ruin a dish.
Save for the trill, ornaments have been realized the same way in all eras; ornaments, when present in the score, are a necessary and integral part of the music -- important thematic elements put there by the composer for good and sufficient reasons to be observed in performance just as much as any other notes written into the score whenever that score is a faithful copy of the autograph.
One needs to be very careful therefore, when the autograph is missing, about performing ornaments appearing in parentheses inserted by various editors based upon a single copy, or copies of copies, or maybe adorning the work ourselves with whatever additional ornamentation suits our fancy to the fullest extent possible; the performance of a very well known and famous work showered with a liberal sprinkling of ornaments foreign to the score can so distort the melodic contour of a melody as to make it unrecognizable and turn it into something the composer never intended.
When most, if not all, extant copies of an early work are traceable to and agree with a single copy, then the ornaments appearing in that single copy are to be regarded as the most correct, if not definitive, reading.
The notes indicated with the ornament pictograph in the score are an integral part of the music and not to be considered optional or changeable.
It's entirely possible for an otherwise outstanding recording of a well-known organ work on a period instrument to be spoiled by the well-meaning additions of ornaments, exchanging of ornaments, or prolonged, florid cadenzas inserted under the smug guise of increasing its stylistic authenticity.
In recent years there has been renewed interest in Baroque performance practices including the license to contribute to the work almost as much as the composer; someone may want to put this writer in the pillory for saying so, but no matter how exciting, unique, or impressive the results of this may sound or how flamboyant the mannerisms, if any, in which an organist engages when exercising such liberties, this kind of tampering still places the performer, whether they are oblivious to it or not, on a slippery slope [See blog, Bach d minor, Part V].
We notice something of the same thing in writing or improvising codas; if the choice is between the longer or shorter of 2 versions, the shorter one is generally preferable; it's a case of less being more [See blog, Less Is More].
One of the best resources in print which may be recommended for working through this complex and interesting subject is "Ornamentation, A Question & Answer Manual, by Valery Lloyd-Watts and Carole L. Bigler, with the assistance of Willard A. Palmar" available from Alfred Publishing Co.; this well-known and well-written book explains essential ornaments clearly and concisely just as they are used in each of the style periods of Western music, why each ornament should be played as recommended as well as how it should be played, and provides all the necessary tools to school one's self in their performance.
Performers who are familiar with this book should be able to look at a piece of music and tell exactly what ornaments are appropriate for use in any given passage by any composer of any era and how they should be realized; the required knowledge for being able to do this follows specific rules which, thanks to this book, have been made much easier to grasp.
(con't in Part XXXIX)