Score:  The written depiction of all the parts of a musical ensemble with the parts stacked vertically and rhythmically aligned.

Secco:  "Dry." Unornamented.

Second:  The second degree of the diatonic scale. Also, the interval formed by a given tone and the next tone above or below it, e.g. c up to d, or c down to b. Intervals of the second may be major, diminished, or augmented.

Section:  A division of a musical composition.

Segno:  "Sign."

Sehr:  Very.

Sehr leise beginnend:  Very soft in the beginning.

Semitone:  A half step. The smallest interval on the keyboard.

Semplice:  Simple.

Sempre:  Always. Used with other terms, e.g. sempre staccato.

Senza:  Without. Used with other terms, e.g. senza crescendo.

Septet:  A piece for seven instruments or voices. Seven performers.

Sequence:  The repetition of a melodic pattern on a higher or lower pitch level.

Serenade:  A love song or piece, usually performed below someone's window in the evening.

Sereno:  Serene, peaceful.

Seventh:  The seventh degree of the diatonic scale. Also, the interval formed by a given tone and the seventh tone above or below it, e.g. c up to b, or c down to d. Intervals of the seventh may be major, minor, diminished, or augmented.

Seventh chord:  When a seventh (above the root) is added to a triad (root, third, fifth), the result is a seventh chord, e.g. the dominant triad in the key of C major, g-b-d, with the added seventh becomes g-b-d-f and is labelled V7.

Sforzando, Sfz, Sf:  Sudden strong accent on a note or chord.

Sharp:  A symbol which raises the pitch of a note one-half step.

Sheet music:  An individually printed song, most often for voice, piano, guitar,or a combination of the three. Any printed music.

Shifting meter:  The changing of meter within a composition. Synonymous with changing meter.