The Short

absence of firm information about a composer's intentions in general or in particular instances, they may be helpful to
the uncertain performer. Eva and Paul Badura-Skoda recommended a main-note start when:
1. in legato the trill is preceded by the next note above;
2. the trill is preceded by three rising or falling notes like a ‘slide’;
3. the trill is on a dissonant note;
4. the trill is in the bass;
5. the trill comes at the end of a rising scale;
6. the trill is preceded by the same note as a sharply attacked anacrusis;
7. the trill is part of a chain of trills; 919
8. the trill is in the formula [Ex. 13.55];
9. in other special cases. 920
Ex. 13.55.
Frederick Neumann proposed a simpler rule of thumb, which he saw as ‘rooted in musical logic’. He suggested that
1) a trill starting with the upper note on the beat has the effect of a short appoggiatura; 2) a trill starting with a
lengthened upper note has the effect of a long appoggiatura; 3) a trill starting with the upper note before the beat
has the effect of a grace-note [in his terminology, a note sounded before the beat]. We find guidance by leaving out
the trill and judging whether one of these ornaments would be a desirable addition to the bare melody; if so, the
corresponding trill type is likely to be the proper or at least an acceptable choice. Where none of these ornaments
seems to fit, the main-note trill is indicated. 921
These are all perfectly good and sensible recommendations, and can to some extent be supported by theoretical
writings; but it may be legitimate to maintain a degree of scepticism about assuming too readily that what seems
musical and tasteful to us in these matters would necessarily have done so to musicians of previous generations.
Trill Endings
APPOGGIATURAS AND GRACE-NOTES 497
There were as many views about the endings of trills as about their beginnings, and here, too, it seems unlikely that
experienced executants would have been greatly inhibited by the composer's notation in varying the endings as they
saw
919
But see the evidence of the Haydn clock (above) with respect to a rising chain of trills where each begins with the upper note.
920
Mozart-Interpretation (Vienna and Stuttgart, 1957), trans. Leo Black as Interpreting Mozart on the Keyboard (London, 1962), 111–16.
921 Ornamentation and Improvisation, 114.