arpeggiate (verb): sounding the notes of a chord, but not simultaneously : Arpeggiate the chord to add a nice texture to the music, especially on a harp.
avant-garde (noun or adj.) in the arts, those who experiment; or describing those who experiment. From French, meaning "those that go before" or "the front line" : I don't understand what I just saw, but it seemed artsy and pretentious. It must be avant-garde.
ballad (noun): a song narrating a story in short stanzas, often with a key phrase repeated throughout : By the 22nd verse of the old man's ballad, the murdered woman's breastbone had been strung with her hair to make a harp played at her murderer's wedding.
beat (noun): a regular, rhythmic pulse. Can be fast or slow, strong or weak : You can't stop the beat, unless you take away my drum.
bowing (noun): the way a string player moves their bow to create different effects : The music was from Thor, so I tried martellato bowing.
bridge (noun): in a popular song, a section of new, contrasting music that links repeated sections, usually the chorus; also called a release : It's a good thing they put the bridge there, otherwise we'd get sick of that chorus.
cacophonous (adj): describing a conflicting mixture of sounds : Though I think two bands marching past each other playing different songs is cacophonous, Charles Ives thought differently.
canon (noun): 1. a list of works commonly accepted as the highest caliber. 2. A compositional strategy in which the same exact melody appears in several parts, but with staggered entrances; a round is a canon at the unison : How did Pachelbel's canon(2) make it into the string players' canon(1)?
CBGB (noun): An acronym for Country, BlueGrass, and Blues, a bar and music club in Manhattan that become the most influential alternative Punk and New Wave venue in America in the late 70s and early 80s : Although CBGB is not really musical vocabulary, it comes up enough popular music discussions that you should know it.
choral (adj.): sung by or associated with a choir or chorus : Choral music is comparatively easy to produce; all you need is singers, and maybe music and a piano.
chorale (noun): 1) a four-part harmonization of a hymntune, especially in the Lutheran tradition, or 2) a choir or choral society : Our chorale is singing many Bach chorales a'cappella.
chordophone (noun): a family of musical instruments producing sounds waves by the vibration of strings : I have a theory, which I call my string theory—chordophones are the most beautiful instruments around.
conductor (noun): a person who leads a large group of performers in collective music-making, usually through gestures : The conductor's expressive leading really galvanized the choir.
cover (noun): a new arrangement or version of a popular song performed by an artist other than the original : Metallica's "Enter Sandman" has some great covers, like a jazz version by Pat Boone and a kazoo version by Mr. Tim.
counterpoint (noun): two or more melodies of equal importance that sound simultaneously and complement one another : In writing, counterpoint works against the point, while in music, the counterpoint works together and that's the point.
drone (noun): a sustained note, usually in the bass, or the instrument that produces the note : I've decided to build my next piece around a lawnmower drone. It sounds better than a highland bagpipe.
dynamics (noun): the volume of sound (soft to loud), determined by the size (amplitude) of the sound wave : Choir, please use dynamics to make the piece more exciting. Or : I jumped with surprise at the loud dynamic!
encore (noun): when a musician or music group performs one or more numbers after the scheduled end of the concert, usually due to positive audience feedback. From the French encore, meaning roughly "ongoing" : After a third unwanted encore, the audience sat firmly on their hands hoping the terrible act did not get onstage again.
eponymous (adj.): giving your name to something else, usually an album; or the group and a particular album have the same name : The Band's eponymous album.
glissando or gliss (noun): sliding between notes. Commonly done on string instruments or the trombone : That loud motorcycle driving by sounded just like a trombone glissando. Thanks, the Doppler effect!
harmonic motion (noun): the pace at which underlying chords change : Wow, the harmonic motion in this music is glacial. Maybe it’s by Philip Glass.
harmony (noun): the sound created by simultaneous musical voices. Can be dissonant or consonant, wide or close, thick or sparse. This term is more general than chord, which refers to harmony in a specific instant : Jazz harmony often features close, constantly changing chords.
hook (noun): in popular music, a memorable, repeated melodic phrase or motive : What makes this pirate song stand out is not the verse or chorus, but the hook in the intro.
idiophone (noun): a family of musical instruments producing sounds waves by the vibration of a material other than strings, air, or membranes : Only an idiot wouldn't figure out how to play an idiophone—you only have to hit the thing!
jam (adj.): usually modifying either band, song, or session, denotes that the music is often lengthened extensively with instrumental solos : That jam band stretches their songs out more than the Grateful Dead.
J-pop (noun or adj.): short for Japanese popular music, this label was originally used for Western-style popular music in Japan, but since 1990 has gradually come to mean any Japanese-language popular music, though some artists in genres such as rock or indie discourage its use to describe their music : My parents' favorite J-pop genre is enka.
Leitmotif (noun): A German word used to describe a brief and malleable musical idea connected to a person, event, item, or concept : You know that Darth Vader is on the shuttle before you see him, because the brass is playing Vader's Leitmotif.
lyric (usu. lyrics; noun): the word of a song : I found the song's lyrics, but I can't seem to locate its music.
lyric (adj.): describing a light singing voice : the lyric soprano had a hard time singing Wagner.
lyricist (noun): a person who writes words that are set to music : Who was the lyricist: Gilbert or Sullivan? Rodgers or Hammerstein? (Answer: Gilbert and Hammerstein, though Gilbert might prefer the opera-oriented term librettist)
MP3 (noun): short for MPEG-1 (or MPEG-2) Audio Layer 3, a type of digitally compressed music file that drastically shrinks the amount of storage space necessary for a digital recording by reducing the quality of a sound, but mostly those parts of the sound outside perceived hearing : A typical MP3 takes up 1/11 the storage space of its CD counterpart; can you even shake a stick at that?
melody (noun): a string of related music notes occurring over time. Though often memorable or hummable, does not have to be either : The flautist played a long and angular melody.
modal (adj.): usually refers to music based on modes other than major or minor : The usual tonic-dominant tonal framework doesn't necessarily hold in modal jazz and folk music.
mode (noun): scale or sequence of notes used as the basis for music; in Western music, the most commonly-used modes are major and minor : Debussy enjoyed switching his melodies' modes as his pieces developed; you should try it yourself, sometime.
motive (noun): the smallest recognizable melodic or rhythmic unit in music and used as building blocks for the construction of melodies : That short, quick motive really gets me going; how motivational!
multivalent (adj.): open to many interpretations or meanings : instrumental music, since it isn't connected to lyrics that dictate its meaning, is multivalent.
oratorio (noun): an opera with no costumes, sets, or staging, and often featuring prominent chorus numbers : Wow, these oratorio tickets were much cheaper than opera tickets, but the music is just as good. Who needs sets and costumes, anyway?
orchestra (noun): 1) a group of instrumentalists, especially one that combines the string, woodwind, brass, and percussion families or 2) the space in which such a group performs : I heard the orchestra play a Classical symphony, a Baroque suite, a Romantic overture, and a modern hoe-down—it's a versatile ensemble.
outro (noun): similar in texture to an introduction, but happens at the end of a song. Usually fades out : Wait, is the song starting over again? No, it’s just an outro.
overtone (noun): in all natural sounds, the series of less prominent higher pitches over than the perceived (fundamental) tone, determining the timbre of the sound. The frequencies of these overtones follow a pattern called the harmonic series : A clarinet's unique timbre comes from only producing every other overtone in the harmonic series.
parody (noun, verb): an imitation of (or to imitate) an artist's work, usually for comic effect and often critiquing its source; in music, this usually takes the form of lyrical invention on a popular melody : To parody is more than to parrot, as the changes highlight instead of obscure.
pentatonic (adj.): relating to or based on any five-note scale, though most commonly denoting a scale without half-steps used in many folk traditions worldwide : Because the pentatonic scale lacks half steps, anything you play using it sounds consonant.
phrase (noun): a group of notes forming a distinct unit within a longer passage. Ends with a cadence : I've had this one phrase from this one song stuck in my head—it's an earworm.
pitch (noun): a quantitative measure of the frequency of a sound wave perceived by our ears; faster frequencies are perceived as higher and slower frequencies are perceived as lower. Used mostly to discuss being “in tune” (or coordinating simultaneous frequencies. It’s mathematics, actually) : Man, your pitch was way off on that note.
plectrum (noun, pl. plectra): a tool used to pluck the strings of a musical instrument : Has anyone seen my guitar plectrum? You might call it a pick.
pre-chorus (noun): a formal section of some popular songs characterized as a bridge from the verse that builds toward a goal (usually the chorus). Often features the same lyrics each recurrence : Hmm, I'd say that was a chorus, but it seems to simply set up the next section of music; maybe it's a pre-chorus.
programmatic music (adj. + noun): music that a composer willfully associates with an extra-musical narrative. Can be a loose connotation or a blow-by-blow sequence of events : Is all music featured in Fantasia programmatic, even if the composers didn't intend to associate their music with a story?
pseudonym (noun): a fictitious name assumed to produce art : The mononymic artist Prince adopted an unpronounceable glyph as a pseudonym because he was mad at his exploitative record label.
reel (noun): a moderate to fast Celtic dance in 2/4 or 4/4 (duple time), usually with a slight accent on the off-beat : While the jig seems to be the most well-known Irish dance by non-Irish, inside Ireland the reel is king.
riff (noun): a repeating melodic idea that generates momentum or motion, generally used in popular music song construction : That guitar riff sounds so good you can repeat it until your fingers bleed. No, wait, I didn’t mean that literally!
rhythm (noun): organization of pitches over time; or any particular durational pattern : Fascinating rhythm, you've got me on the go! Fascinating rhythm, I'm all a-quiver.
signifier and signified (noun): the two parts of a sign; the signifier is the physical form, and the signified is what the sign stands for : On the road, the red octagon is the signifier for stop (which is the signified); In written music, the double bar line at the end of a measure is the signifier for stop.
tempo (noun): the speed of music's underlying pulse : Despite the song's slow tempo, the saxophonist played a lot of notes very quickly.
texture (noun): the amount of melodic layering in music and how these layers interact; can be thick or thin : In that piece, Bach presents four different melodies at the same time to create a thick fugal texture.
theme (noun): A recognizable, reoccurring musical phrase often based in a certain key area : When the second theme returned, I noticed it was in a different key—maybe the movement is in sonata form.
timbre (noun, pronounced [TAM-br]; also called tone color): the character or quality of a musical sound, determined by the prominence of its acoustic overtones : That tambourine really adds a nice timbre to the percussion sound.
to vamp (verb): repeating a short musical riff or phrase many times, usually waiting for a cue to move on : The score said to vamp until the stage dialog was finished, but they were so slow, we ended up repeating the measures like 100 times!
venue (noun): A building or place that sponsors events, musical or otherwise : There's this venue where you can watch live music while you jump on trampolines—now that's a mosh pit!
unpitched (adj.): describing any instrument that produces sound of indeterminate pitch; usually referring to percussion : While you can hear the pitch of a timpani, snare and bass drums are unpitched.
vinyl (noun): short for a phonograph record made with polyvinyl chloride, sound is recorded with an analog signal on a spiral grove and played back with a needle; common rotational speeds are 33 1/3, 45, and 78 : While new vinyl purchases are on the rise, it's still a niche market made up mostly of audiophiles.
virtuoso (noun): a highly skilled performer in their particular field : Paganini, a famous talented violin player in the 19th century, is considered the first modern virtuoso.
zydeco (noun): the traditional music of the Creole people in the gulf region of the USA, particularly southwestern Louisiana; the music features mixed European (esp. French) and African influences : Zydeco musicians tend to me more black and urban than their Cajun counterparts and features more percussion, though accordion still leads in both groups.