These apply mainly to instrumental (orchestral, chamber and solo) genres.
This is an expanded summary of what we discussed on March 17, 1999.
MELODY &  SCALE Longer phrases, few breaks or pauses, rhythmically somewhat complex, use of sequences to build momentum; paired phrases uncommon Short phrases, phrase symmetry and/or balance; tendency for dualistic contrast between parts of a phrase; pairs of phrases ("antecedent-consequent") are common Longer phrases and more songlike than classical melodies, may use chromaticism; definite tendency to work toward melodic peaks; usually very "expressive" Tonality is generally "expanded" to other scale types (modal, whole-tone, and synthetic or exotic scales); exception may be chromatic scale which is seen as holdover from 19th century; however, chromaticism itself is used freely; tendency to be more disjunct (wide skips, frequent changes of direction); difficult to generalize from one composer to next; some completely abandon melody in the traditional sense; a few composers use "microtonal" scale systems
HARMONY & TONALITY Major-minor tonal system fully established by 1680-1700; prior to that sense of major/minor is weaker; modulation (change of key) is mainly to keys differing by only 1 sharp or flat from the home key; rate of chord change ("harmonic motion") is rapid; bass line moves around a lot Harmonic motion slower than that of baroque (more notes, fewer chord changes); bass line is more of a harmonic support than a melody; modulation and chromaticism confined to relatively specific places in the form of the piece; key changes only mildly more adventurous than baroque Harmonic motion remains slow; chromaticism increases; distinction between major and minor is often blurred; modulations to remote keys and "chromatic modulations" become frequent; sense of being in a key often weakened; harmony sometimes seems "vague" or ambiguous; more complex chords (7th and 9th) are used; somewhat more dissonant than classic and earlier Tonality (sense that chords progress toward a harmonic goal) breaks down in some music, is maintained but in an expaned form in others. Many composers experiment with new approaches to tonality and harmony--bitonality (playing in 2 keys at once), modality (using the old diatonic modes in new ways), atonality (free use of dissonance, no feeling of a tonic), and serial techniques such as 12-tone system (Arnold Schoenberg and others) (using a predetermined series of pitches as a basis for structure)
RHYTHM Motor rhythms, especially in fast tempos, tendency for very regular patterns; rhythmic "layers" (bass in slow notes, upper parts in faster notes); emphasis on a clear, regular pulse; tempos are very steady within movements Rhythmic structure tends to be governed by the phrase rather than the beat or measure; thus two different phrases can have an entirely different rhythm; tempos tend to remain steady within movements, with more freedom for pauses and slowdowns than in baroque Somewhat freer rhythmic structure than classic; the beat is often de-emphasized, both by use of rubato and by the use of syncopation and other blurring techniques; it is often harder to tap foot to Romantic music Highly variable: some music appears to have no beat whatever while others go back to the "machine beat" of baroque music. Still others (e.g. Stravinsky) often have a strong rhythmic feel but the meter (and sometimes the beat itself) are asymmetric. There can also be a great amount of variability within a single piece. Rubato, however, is less common than in the 19th century.
TEXTURE Tends to be polyphonic, with emphasis on polarity between top voice and bass. Texture tends to be uniform throughout a movement, with some exceptions in certain types of pieces Homophonic, with occasional polyphonic sections within movements. Slow harmonic change in relation to level of rhythmic activity (Lots of notes, few changes of chords) Still primarily homophonic but with greater attention to countermelodies and incidental inner part motion. Texture can range from simple to very complex Tends toward polyphonic and complex, but again no hard and fast rules apply
FORM Continuous within movements, long phrases, few breaks at cadence points. One main theme or head motive, which tends to be repeated at intervals throughout movement, separated by episodes Sectional Form (Clear phrase breaks, sections tend to have contrasting moods and purposes (theme statement, transition, closing, developmental). Balance occurs at phrase, section and movement levels; form governed by key relationships (themes and sections originally appearing in a non-tonic key are restated later in the tonic) Primary form models still those of later 18th century. Size of form and length of movements is expanded. Phrases may be less clear-cut with tendency to avoid form-defining pauses. Music takes on more of a narrative structure with result that "form" is less obvious; Key relationships are less clear; whole movements are often linked musically by transition passages; cyclic form used for symphonies; one-movement forms popular (e.g., symphonic poem
PROGRAM MUSIC the rule; even pieces with abstract titles (like "Symphony No. 1") can sound like they are "about" something beyond music
Impossible to generalize. Some composers continue formal types of 19th century with modifications; others base music on earlier centuries; still others try to develop totally new formal schemes, with tendency for overall form to be an expansion of a central idea; a few composers question the notion of form itself, and experiment with "chance" approaches where any particular performance of a work has a degree of unpredictability.
DYNAMICS Dynamics tend to be determined by number of instruments playing at a given time; otherwise "terrace" dynamics (sudden contrasts of loud and soft) are used. Crescendo and diminuendo generally not used. Dynamic range f to p Dynamics begin to play important role in shaping structure--contrasting themes often have contrasting dynamics; crescendo and diminuendo used for dramatic effects; dynamic range extended to ff and pp Dynamics used more flexibly within single phrases (more frequently written into the score); range increases to fff to ppp and beyond Number of dynamic indications in score increases, with some composers assigning a dynamic to every note. Many pieces feature violent juxtapositions of loud and soft. Crescendo and diminuendo used less often and then by more "conservative" composers
FEELING AND MOOD One feeling or mood tends to prevail within a movement, due to lack of textural and thematic contrast
Dualism of themes means contrasting moods; actually, moods tend to fluctuate between areas of "stability" (theme statements) and "instability" (transitions and developments)
Mood and feeling can vary within a single theme or even phrase; tends to be determined by rhythm, tempo and tone color as well as degree of dissonance, chromaticism or tonality
Impossible to generalize; some music seems very cerebral, other seems to maintain one mood throughout while still other features violent mood swings with emphasis on more "troubled" emotion or emphasis on shock and surprise
INSTRUMENTATION In orchestral music, strings prevail with very occasional use of winds; continuo is present (Harpsichord or organ, plus a bass instrument) Continuo goes out of fashion; size of orchestra increases somewhat; woodwinds in pairs added; Brass usually 2 horns, can be expanded to add 1-2 more horns, 2 trumpets and timpani Orchestra size increases greatly (>100 players); brass expanded to include trombones and tuba; woodwind section expanded on high and low end (piccolo, bass clarinet, contrabassoon are common additions); percussion, harp and other keyboard isnts. including piano and organ are fairly common esp. toward end of century Earlier, large orchestras prevail; after World War I, smaller ensembles become more common; instrumentation varies; electronic instruments (synthesizers) begin in 1950s as does computer music; exotic (non-Western) instruments used for color purposes by some