Stems.
[22.]—There is no rule as to the length of stems, and they vary greatly. The stems in a single group of notes are as often as not of different lengths, according to the position of the notes and the direction taken by the hook. A common fault is to make them too short, especially when the four hooks of a sixty-fourth note have to be added. This, however, is generally the result of a badly directed hook (see a, [Fig. 18]).
[23.]—As to the direction they take there is a definite rule. In open score (when one part only is being written on a stave), the stems of notes above the middle line should be turned down, the stems of those below the middle line should be turned up (see b, [Fig. 18]). The object of this is to keep the stems within the stave and prevent their sprawling above or below. The ill-equipped writer betrays himself by nothing more often than by sprawling stems.
The stems in a group of notes are generally turned according to the direction of the first note, or the majority. In a group containing a wide skip they are often turned individually according to the rule, involving opposite directions, the hook being drawn between them (see c, [Fig. 18]).
Five exceptions are common: (1) The stem of a grace note is almost invariably turned upwards, though according to Dr. Hullah it should be turned in the direction contrary to that of the stem of the principal note, for the sake of greater distinctness (see d, [Fig. 18]). In “copy” for the printer grace-notes are best written in red ink. (2) In piano music when a single part, or row of notes, is to be divided between the hands, one playing one group and the other the next, the stems of the right-hand notes are turned up, and those of the left down (see [Fig. 15], latter half of measure). (3) Similarly in some organ music, especially that printed in Germany, pedal notes which are to be played by the right foot have the stems turned up, those by the left, down. (4) In vocal music, when a subsequent verse, though having the same notes, requires different time-values from the first verse, or a translation requires different time-values from the original language, the time-values required by one verse or language have the stems of the notes turned up, those required by the other down (see e, [Fig. 18], from Molique's oratorio “Abraham”). (5) In music written on two staves, when the notes of a single group skip from one stave to the other, the hook is placed between the staves, and the stems of the notes on the lower stave are turned up, and of those on the upper stave down, irrespective of their relation to the middle line of the stave (see f, [Fig. 18], from the “Moonlight” Sonata).
Fig. 18.
[24.]—In short score, that is when two parts have to be written on one stave, the stems belonging to the upper part should be turned upwards, and those to the lower downwards. Only by this means can the course of the parts be made clear to the eye. When the parts cross, the rule must be strictly adhered to: the note belonging to the upper part, not the upper note, must have the upward stem. To make quite clear which note each stem belongs to, it is well in this case to make the notes a little less close together than they otherwise would be (see a, [Fig. 19], a well-known case from a chant by Sir John Goss, where the tenor goes below the bass). Sometimes more than two parts are written on one stave; in this case the stems of two parts must be turned the same way, and considerable ingenuity is required to make the course of the parts clear. Usually the middle part varies in the direction of its stems. Simultaneous notes are generally written not quite in a line with each other, to allow of separate stems: the stems are generally rather short, so as not to run into each other, and the hooks of simultaneous eighths and shorter notes do not concur. Two measures from Bach's piano fugues will illustrate these points (b and c, [Fig. 19]).