What are the most common ways to "decorate" a melody?

Question

Yes, I know, there are way too many possibilities and it depends on the style of the music... I would be happy with an incomplete list for beginners (like me). Here is what I have so far:

1. Accompanying triads, very common in fake books, see also
   How do I make piano chords sound interesting when playing along with popular songs?
2. Melody played on two notes, with exactly one octave distance
3. Dyads
4. Ornaments

What other ways are there to "decorate" a melody?

I expect a list of the most common techniques + links to explanations (if needed), just as above.
Do not go into details about the myriad of variations of a particular technique.

Answer 1

The art of Counterpoint, as studied by composers for centuries, gives exact details on how to correctly ornament any melody. The lists of ornaments cited as point 4 in the question is only a subset of the possibilities given to us by counterpoint.

There are five main species of counterpoint. The treatise by Johann Joseph Fux is today the most common source for an in depth description of counterpoint. In a nutshell, species counterpoint categorizes intervals into consonant (octaves, perfect fifths and fourths, and major and minor thirds and sixths) and dissonant (seconds, sevenths, and tritones). Then, it gives guidelines for the placement of intervals based on the pattern of strong and weak beats.

Note that in all the examples of counterpoint given here (images are from wikipedia), the added melody is the top voice. These same counterpoint rules can apply to any melody that also has an accompanying harmony (as described in point 1 in the question above).

• First Species: Also note against note counterpoint. Since all pitches fall on downbeats, all intervals must be consonant.

  

• Second Species: Two notes in the counterpoint voice are set against each note in the given voice. The intervals on the downbeats should be consonant intervals, whereas the second note can be consonant or dissonant. When dissonant, the best choice is either a passing or neighbor note.

  

• Third Species: Four notes against one. This species extends the use of dissonances in second species. The first and third notes of every four-note group should be consonant while the second and fourth may be dissonant.

  

• Fourth Species: Here, notes in the upper voice are suspended over the bar line, often creating a dissonance on the downbeat of the bar. When dissonant, the upper voice must resolve downward to a consonant interval.

  

• Fifth Species: This species combines the methods described in the previous four. The example shows how this species can be used to create well ornamented melodies in a free style.

  

Species counterpoint can at first seem very limiting, but through its practice, it can be used to create very exciting melodies and counter-melodies. Knowing how and when to use consonance vs. dissonance allows complete control over the design of a melody.

Answer 2

Ornamentation is the process of adding little "points of interest" to accentuate the drama of the melody.

• Passing Tones add a moment of slower "pace" to a melody. Instead of flying, jumping, or teleporting to the destination, this poor schmo has to take each step one at a time.

• Grace Notes add a bit of "trajectory" to melody. There's an older style slow grace note which happens on the beat and pushes the real note forward. The newer cut grace notes (sometimes notated with a slash through the stems) happen just before the beat (perhaps with a little push on the real note for a slight "syncopation" effect).

• Trills add a bit of "pizazz" (for want of a better term). Think "jazz hands" from IIRC Bring It On 2 (You know you've seen it; ain't foolin' nobody!). Unless explicitly notated funny (like in some Chopin works), the "correct" way to play these is to start on the Upper Note, then down, up-down, up-down.

• Mordents add a little "twirl". Like a pirouette. Or a dog turning a few circles before lying down. It emphasizes the arrival at this point.

• Slurs are the opposite of passing tones: one note just glides into the next.

Phrasing and Articulation effects can also enhance a melody.

• Legato each note "touches" the next for a continuous, unbroken sound.

• Staccato each note "pops" out of nowhere and dissolves away to silence before the next.

• Tenuto soft of halfway between Legato and Staccato; each note "sings" but with just a little bit of punctuating silence to keep them distinct.

• Sforzando is a Forte Staccato out of left field!

• Subito or Subito Piano is a sudden quiescence. It can be really spooky.

Answer 3

Yes, typical ways that cocktail pianists use to decorate the melody include:

• using 6ths
• using 3rds on top
• chromatic connecting tones between key chord tones
• adding dominant chord approaches to tonic chords (eg. E7b13 > Am) or pieces of such chords
• adding diminished passing chords, or pieces of such chords
• "mild" forms of improvisation on basic chord tones and allowed tensions for that chord
• using the "allowed" improvisational tones for a chord to target the melody tone
• stripping out superfluous melody tones (ie those that do not fall on the downbeat) and replacing them with other tones from the key scale

Answer 4

One of the other answers gives a mixture of traditional ornaments like trill and mordent along with "passing tones." It's a nice list, but "passing tones" are only one type of "non-chord tone" (NCT) and I think a fuller list of NCT's should be given:

• Passing Tones
• Neighbor Note
• Suspension
• Anticipation
• Appoggiatura
• Escape tone
• Cambiata (or changing tones)

All of these and some others are defined with notated examples at Wikipedia https://en.wikipedia.org/wiki/Nonchord_tone

Keep in mind that while the terms are from formal music theory, the actual "melodic moves" they describe are used in virtual every musical style including pop and rock.