fancyyoudaoicibaDictYouDict
fancy: [15] Ultimately, fancy is the same word as fantasy [15], from which it emerged by a process of contraction and gradually became differentiated in meaning. Both go back originally to the Greek verb phaínein ‘show’ (source also of English diaphanous and phenomenon). From it was derived phantázein ‘make visible’, which produced the noun phantasíā ‘appearance, perception, imagination’ and its associated adjective phantastikós ‘able to make visible’ (and also incidentally phántasma, from which English gets phantasm and phantom).

The noun passed into English via Latin phantasia and Old French fantasie, bringing with it the original Greek senses and also some others which it had picked up on the way, including ‘caprice’. The semantic split between fantasy, which has basically taken the road of ‘imagination’, and fancy, which has tended more to ‘capricious preference’, was more or less complete by about 1600.

The quasi- Greek spelling phantasy was introduced in the 16th century, and has persisted for the noun, although the contemporary phantastic for the adjective has now died out. The Italian form fantasia was borrowed in the 18th century for a fanciful musical composition. (Fancy and fantasy have no etymological connection with the superficially similar fanatic, incidentally, which comes ultimately from Latin fānum ‘temple’.)

=> diaphanous, fantasy, pant, phantom
ballade (n.)youdaoicibaDictYouDict
late 14c., an earlier borrowing of ballad (q.v.) with a specific metrical sense. Technically, a poem consisting of one or more triplets of seven- (later eight-) lined stanzas, each ending with the same line as the refrain, usually with an envoy. Popularized 19c. as a type of musical composition by Frédéric Chopin. Ballade royal is recorded from late 15c.
bass (adj.)youdaoicibaDictYouDict
late 14c., of things, "low, not high," from Late Latin bassus "short, low" (see base (adj.)). Meaning "low in social scale or rank" is recorded from late 14c. Of voices and music notes, from mid-15c. (technically, ranging from the E flat below the bass stave to the F above it), infuenced by Italian basso. Meaning "lowest part of a harmonized musical composition" is from mid-15c. Meaning "bass-viol" is from 1702; that of "double-bass" is from 1927.
coda (n.)youdaoicibaDictYouDict
"concluding passage in a musical composition," 1753, from Latin cauda "tail of an animal."
diversion (n.)youdaoicibaDictYouDict
early 15c., "diverse condition;" c. 1600 "act of diverting," from Middle French diversion, from Late Latin diversionem (nominative diversio), noun of action from past participle stem of Latin divertere (see divert).

Sense of "amusement, entertainment" is first recorded 1640s. Hence, divertimento (1823), from the Italian form; originally "a musical composition designed primarily for entertainment."
duet (n.)youdaoicibaDictYouDict
1740, from French duet, from Italian duetto "short musical composition for two voices," diminutive of duo "two" (see two). As a verb, from 1822. The Italian form of the noun was used in English from c. 1724.
fantasia (n.)youdaoicibaDictYouDict
"musical composition that sounds extemporaneous," 1724, from Italian fantasia, from Latin phantasia (see fantasy).
fugue (n.)youdaoicibaDictYouDict
type of musical composition, 1590s, fuge, from Italian fuga, literally "flight," also "ardor," from Latin fuga "a running away, act of fleeing," from fugere "to flee" (see fugitive (adj.)). Current English spelling (1660s) is from the French version of the Italian word.
A Fugue is a composition founded upon one subject, announced at first in one part alone, and subsequently imitated by all the other parts in turn, according to certain general principles to be hereafter explained. The name is derived from the Latin word fuga, a flight, from the idea that one part starts on its course alone, and that those which enter later are pursuing it. ["Fugue," Ebenezer Prout, 1891]
glee (n.)youdaoicibaDictYouDict
Old English gliu, gliw, gleow "entertainment, mirth (usually implying music); jest, play, sport," also "music" and "mockery," presumably from a Proto-Germanic *gleujam but absent in other Germanic languages except for the rare Old Norse gly "joy;" probably related to the group of Germanic words in gl- with senses of "shining; smooth; radiant; joyful" (see glad). A poetry word in Old English and Middle English, obsolete c. 1500-c. 1700, it somehow found its way back to currency late 18c. In Old English, an entertainer was a gleoman (female gleo-mægden).

Glee club (1814) is from the secondary sense of "musical composition for three or more solo voices, unaccompanied, in contrasting movement" (1650s), a form of musical entertainment that flourished 1760-1830.
Gradus ad Parnassum (n.)youdaoicibaDictYouDict
Latin, literally "A Step to Parnassus," the mountain sacred to Apollo and the Muses. It was the title of a dictionary of prosody used in English public schools for centuries as a guide to Roman poetry. The book dates from the 1680s. Also the name of a treatise on musical composition written in Latin by Johann Joseph Fux, published in Vienna in 1725, and of a much-used book of exercises for piano.
instrumental (adj.)youdaoicibaDictYouDict
late 14c., "of the nature of an instrument," from Old French instrumental, from Medieval Latin instrumentalis, from Latin instrumentum (see instrument). Meaning "serviceable, useful" is from c. 1600. Of music, c. 1500; noun meaning "musical composition for instruments only" is attested by 1940. Related: Instrumentally; instrumentality.
opera (n.)youdaoicibaDictYouDict
"a drama sung" [Klein], 1640s, from Italian opera, literally "a work, labor, composition," from Latin opera "work, effort" (Latin plural regarded as feminine singular), secondary (abstract) noun from operari "to work," from opus (genitive operis) "a work" (see opus). Defined in "Elson's Music Dictionary" as, "a form of musical composition evolved shortly before 1600, by some enthusiastic Florentine amateurs who sought to bring back the Greek plays to the modern stage."
No good opera plot can be sensible. ... People do not sing when they are feeling sensible. [W.H. Auden, 1961]
As a branch of dramatic art, it is attested from 1759. First record of opera glass "small binoculars for use at the theater" is from 1738. Soap opera is first recorded 1939, as a disparaging reference to daytime radio dramas sponsored by soap manufacturers.
oratorio (n.)youdaoicibaDictYouDict
"long musical composition, usually with a text based on Scripture," 1727 (in English from 1640s in native form oratory), from Italian oratorio (late 16c.), from Church Latin oratorium (see oratory (n.2)), in reference to musical services in the church of the Oratory of St. Philip Neri in Rome, where old mystery plays were adapted to religious services.
pastorale (n.)youdaoicibaDictYouDict
musical composition from rustic tunes or representing pastoral scenes," 1724, from Italian pastorale, noun use of adjective, from Latin pastoralis (see pastoral).
quartet (n.)youdaoicibaDictYouDict
1773, "musical composition for four instruments or voices," from French quartette, from Italian quartetto, diminutive of quarto "fourth," from Latin quartus "fourth" (see quart). Meaning "set of four singers or musical performers" is from 1814.
reverie (n.)youdaoicibaDictYouDict
mid-14c., reuerye, "wild conduct, frolic," from Old French reverie, resverie "revelry, raving, delirium" (Modern French rêverie), from resver "to dream, wander, rave" (12c., Modern French rêver), of uncertain origin (also the root of rave). Meaning "daydream" is first attested 1650s, a reborrowing from French. As a type of musical composition, it is attested from 1880. Related: Reverist.
rhapsody (n.)youdaoicibaDictYouDict
1540s, "epic poem," from Middle French rhapsodie, from Latin rhapsodia, from Greek rhapsoidia "verse composition, recitation of epic poetry; a book, a lay, a canto," from rhapsodos "reciter of epic poems," literally "one who stitches or strings songs together," from rhaptein "to stitch, sew, weave" (see wrap (v.)) + oide "song" (see ode). Meaning "exalted enthusiastic feeling or expression" is from 1630s. Meaning "sprightly musical composition" is first recorded 1850s.
rondo (n.)youdaoicibaDictYouDict
1797, "musical composition of one principal theme, which is repeated at least once," from Italian rondo, from French rondeau, rondel, from Old French rondel "little round" (see rondel).
theory (n.)youdaoicibaDictYouDict
1590s, "conception, mental scheme," from Late Latin theoria (Jerome), from Greek theoria "contemplation, speculation; a looking at, viewing; a sight, show, spectacle, things looked at," from theorein "to consider, speculate, look at," from theoros "spectator," from thea "a view" (see theater) + horan "to see," possibly from PIE root *wer- (4) "to perceive" (see ward (n.)).

Earlier in this sense was theorical (n.), late 15c. Sense of "principles or methods of a science or art" (rather than its practice) is first recorded 1610s (as in music theory, which is the science of musical composition, apart from practice or performance). Sense of "an intelligible explanation based on observation and reasoning" is from 1630s.