Usually the small notes are an indication that they may be omitted by players who have not the stretch of hand necessary to play them.
Accenting a Mordent in a Sonata
How should one play and accent the mordent occurring in the forty-seventh measure of the first movement—allegro di molto—of Beethoven's Sonata Pathétique, Opus 13?
The accent ought to lie upon the first note of the mordent, but you should not make a triplet of it by occupying the whole quarter with its execution. The mordent must be played fast enough to preserve the rhythmic integrity of the melody-note.
The Position of the Turn Over a Note
The turn
stands sometimes directly over the note and sometimes farther to the right of it. Does this difference indicate different executions and, if so, how would the two turns have to be played?
The turn always begins with its uppermost note. When it stands directly over a note it takes the place of this note; when more to the right the note is struck first and the turn, judiciously distributed at the time of its disposal, follows.
How Are Syncopated Notes to be Played?