Stem (music)
Stems can refer to two things in music, relating to music notation and production.
Notation change
Stems are the lines which extend from the notehead. Stems may point up or down. Different-facing stems indicate the voice for polyphonic music written on the same staff. For single-note melodies, the stems usually point down for notes on the middle line or higher, and up for those below. If the stem points up from a notehead, the stem starts at the right-hand side of the note, but if it points down, it starts from the left. The exception to this rule is when a chord contains a second, in which case the stem runs between the two notes, the higher being placed on the left of the stem and the lower on the right. The length of a stem is usually that of an octave on the staff, going to either an octave higher or lower than the notehead, depending on which way the stem is pointing.
Production change
Stems are the individual parts of a mix, separately saved (usually to disc) for the purposes of use in a remix.
