| Term | Description |
|---|
| Staff | In standard Western musical notation, the staff is a set of five horizontal lines and four spaces, on which note symbols are placed to indicate their pitch. |
| Stanza | In popular vocal music, a stanza is typically referred to as a "verse" (as distinct from the refrain, or "chorus"). |
| Steam whistle | A steam whistle is a device used to produce sound with the aid of live steam. |
| Stem | 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. |
| Steps and skips | In music, a step is a linear or successive interval between two pitches which are consecutive scale degrees. Any larger interval is called a skip. In the diatonic scale, a step is either a minor second or major second, with all intervals of a minor third or larger being skips. |
| Strain | A strain is a series of musical phrases that create a distinct melody of a piece. A strain is often referred to as a "section" of a musical piece. |
| Strings | A string is the vibrating element that is the source of vibration in string instruments, such as the guitar, harp, piano, and members of the violin family. |
| String quartet | A string quartet is a musical ensemble of four string instruments—usually two violins, a viola and cello or violoncello—or a piece written to be performed by such a group. |
| String quintet | A string quintet is an ensemble of five string instrument players or a piece written for such a combination. |
| String trio | A string trio is a group of three string instruments or a piece written for such a group. The earliest string trio form consisted of two violins and cello, a grouping which had grown out of the baroque trio sonata. |
| Strophic form | In music, strophic form (or chorus form) is a sectional and/or additive way of structuring a piece of music based on the repetition of one formal section or block played repeatedly. |
| Subdominant | In music, the subdominant is the technical name for the fourth tonal degree of the diatonic scale. It is so called because it is the same distance "below" the tonic as the dominant is above the tonic - in other words, the tonic is the dominant of the subdominant. It is also the note immediately "below" the dominant. |
| Subject | In music, subject is the first melodic fragment of a fugue. |
| Submediant | In music, the submedian is the sixth tonal degree of the diatonic scale. It is so called because it is a step below the mediantonic, in contrast to the mediant being a third above the tonic. |
| Suite | In music, a suite is an organized set of instrumental or orchestral pieces normally performed at a single sitting, as a separate musical performance, not accompanying an opera, ballet, or theater-piece. |
| Supertonic | In music or music theory, the supertonic is the second degree or note of a diatonic scale (in other words, immediately "above" the tonic). |
| Sustain | Sustain is a parameter of musical sound in time. As its name implies, it denotes the period of time during which the sound is sustained before it becomes inaudible. |
| Sustain pedal | A sustain or sustaining pedal (also damper pedal or loud pedal) is the most commonly used pedal in a modern piano. It is typically the rightmost of two or three pedals. When pressed, the sustain pedal "sustains" all the strings on the piano, removing the dampers from all strings and allowing them to vibrate freely. |
| Swiss army triplet | In percussion, a Swiss army triplet is a rudiment consisting of a right hand flam followed by a right tap and a left tap, or (using a left hand lead) a left hand flam followed by a left tap and a right tap. |
| Swung note | In music, a swung note or shuffle note is the rhythmic device in which the duration of the initial note in a pair is augmented and that of the second is diminished. |
| Symphonic poem | A symphonic poem or tone poem is a piece of orchestral music in one movement in which some extramusical program provides a narrative or illustrative element. This program may come from a poem, a story or novel, a painting, or another source. |
| Symphony | A symphony is a musical composition, often extended and usually for orchestra. |
| Syncopation | In music, syncopation is a stress on a normally unstressed beat, or a missing beat where a stressed one would normally be expected. |
