Turning now to Mozart and his two surviving bassoon works, the Concerto in B-flat, and the Sonata in B-flat, K. 292. Mozart's ornamentation is of course different from Vivaldi's, but in some features it is closer to Vivaldi than to, say, C. P. E. Bach, who is still, unfortunately, considered by too many as the chief authority for all masters of the 18th century.
Mozart is among many masters whose performances have suffered, and continue to suffer, from his subjection to C.P.E.'s rigid rules. Many of us forget that in musical matters Austria in the 18th century was looking to Italy and not to northern Germany.
On the subject of ornamentation, it seems that in the two works cited above the problems are essentially limited to the following: the Vorschlag, in its two forms of grace note and appoggiatura, the trill, the Eingang, and the cadenza.
Eingang, meaning "lead-in," is Mozart's own term for an introductory passage that leads into a theme. Often written out, but also often left to the performer's improvisation, as is the case in both the concerto and the sonata, the Eingang is signified by a fermata on the dominant chord of the prevailing key or on a rest following the dominant. The Eingang's most characteristic occurrence is in Rondo movements connecting the end of a section with the re-entry of the refrain. Mozart's spelled-out Eingang are occasionally long, but, for the most part they consist of only a few notes such as a scale or similar figuration. I think it is wise to look for our models to Mozart's short specimens by doing only what is necessary without getting too loquacious. There are several such Eingange in both the concerto and the sonata that need to be added and I shall have some suggestions.
Cadenzas are introduced by a 6/4 chord on the tonic with fermata, and end typically with a trill on the dominant seventh. They are more substantial, should preferably quote and elaborate on themes or motives from the movement, and should contain some brilliant passage work. Cadenzas should not be too long, should not markedly exceed the technical level of the piece, should not modulate too far afield, and should not jump outside the stylistic framework. In other words, they should neither technically nor stylistically flaunt their character as a foreign implant, one that disturbs the organic unity of the movement.
For symbol -indicated ornaments, here notably the trill and the Vorschlag, there are not pat solutions. There are cases where the solution seems obvious, others where there is more than one possible way.
Let me emphasize that the textbook solutions whereby each ornament, including the Vorschlag, has to fall accented on the beat, and every trill has to start with the upper note, also on the beat, are simply not applicable to Mozart. Furthermore, the much repeated rule that an appoggiatura before a binary note takes one half of the latter does apply occasionally, but by no means always, even though endorsed by Leopold Mozart, The companion rule whereby an appoggiatura before a dotted note takes two thirds of the value rarely applies to Mozart, and if so, only before short notes.
Mozart's trill, following a long-standing Italian tradition, is essentially a main note trill. This is true to the point where one can say that the first choice for Mozart's trill should be the start with the main note. There is even much incontrovertible evidence that many of Mozart's cadential trills were of the main note variety.
There are, however, contexts that favor the start with the upper auxiliary. The upper note could be placed unaccented before the beat as a grace note, or accented on the beat as a short appoggiatura. I refer to these types as grace note trill and appoggiatura trill respectively. As a guideline to solving this problem, I suggest leaving out the trill and asking yourself if a short appoggiatura or a grace note could be profitably added to the unornamented note. If so, then the trill could be sensibly rendered accordingly. If neither of these additions is convincing then the start with the main note is indicated.
Regarding the Vorschlag, there are again no hard and fast rules. In contrast to Vivaldi, Mozart uses a variety of denominations to mark the little note, ranging from quarter-notes to thirty-seconds. There is meaning in the various forms, and it is a pity we do not have the autographs of the two bassoon works, because publishers or copyists were often lackadaisical in rendering Mozart's original denominations. But, in general, the ones found in the first edition, which is our main source, do make sense, and Andre, the publisher, was generally reliable.
The denominations give only approximate clues with the longer values standing mainly for appoggiaturas and the smaller values standing for either appoggiaturas or grace notes. There are, of course, exceptions in both, especially in the music of the young Mozart.
Since a bassoonist's main interest focuses on the concerto, I shall now go through it and make suggestions. Please note that the following are suggestions, not prescriptions.
The main note of the trill in measure 38 is an appoggiatura. It makes little sense to place a second appoggiatura on the first. An anticipated auxiliary is both more logical and more graceful.
In measure 39, the repeat of the same pitch on a stressed beat favors an appoggiatura.
The first trill could be either a grace note or main note trill. All other trills in this passage begin on the main note because the repetition of the B-flat or C is thematic.
In measure 64, short appoggiaturas are indicated although a grace note treatment is also possible (tierces coulées).
Since the trill in measure 70 is candential, it can be introduced either by an appoggiatura or a slide.
In measure 95, the upward leaping Vorschlag should be anticipated and treated as a stylized form of a singer's portamento.
Measure 97 presents the first opportunity for an Eingang. A possible model is provided.
In measure 117, the main note of the trill is already an appoggiatura so a main note or grace note trill is indicated.
The trill in measure 136 is tied to the preceding appoggiatura indicating a main note trill.
Using short appoggiaturas in measure 143 is more vigorous than a grace note treatment.
Because of the large leap between measure 150 and 151, a slide trill, one of Mozart's favorite cadential formulas, seems preferable to an appoggiatura trill.
In measures 7 and 8 of the second movement, the first two Vorschlags occur before written-out appoggiaturas, indicating a grace note treatment. In addition, an on-the-beat appoggiatura would result in parallel octaves with the accompaniment. The third Vorschlag should be performed as an appoggiatura.
In measure 11, a short appoggiatura is more expressive than a grace note. In measure 12, the main note of the trill is a written-out appoggiatura indicating the use of an anticipated grace note.
In measures 41 and 42, a main note treatment brings out the characteristic interval of a minor seventh between C and the B-flat above it.
The trill in measure 45 works equally well as either a main note, grace note, or appoggiatura trill.
Because of the leap to the trill in measure 27 of the third movement, a main note trill is preferable.
Measure 106 presents another opportunity for an Eingang. A longer Eingang than the example may be justified here because it is a substitute for a cadenza.
The following suggestions are applicable to the Sonata in B-flat for Bassoon and Cello, K. 292 (I 96c).
The ambiguity of some of the symbols, notably for the Vorschlag, is at the same time a hardship, a challenge, and an opportunity for the performer. The hardship is the occasional agony of choice, the challenge is the need to exert one's judgement and musicianship, and the opportunity is the possibility to vary one's performance from one time to the next.
Ornaments are born of improvisation and must always retain a measure of flexibility to be true to their function. They must never be calcified. Mozart, like all great masters who discussed performance, never spoke of rules, but always of what he called "Gusto," which, like the French goût, is a combination of musicianship and intelligence. As mature performers, you ought to know what the style permits or requires, but you cannot abdicate the responsibility of using your taste and judgement, your "Gusto," in all matters of interpretation including, of course, the rendition of ornaments.
1. To aid the identification of the concertos, they are listed by Fanna (F), Pincherle (P), and Ryom (RV) numbers. The measure numbers are listed as they are in the collected edition, Le opere di Antonio Vivaldi, ed. G. F. Malipiero (Rome, 1947- ).