In a previous article, Writer's Block And Composition Or Songwriting Strategies, I talked about techniques to overcome writer’s block and we examined a couple of composition techniques, among them spontaneous melody writing and the use of rhythmic diagrams.

Today I’d like to examine the strategy for composing a melody to an already existing chord progression. This is probably the most common contemporary technique for melodic composition, and something every jazz player does spontaneously when they’re improvising a solo over a jazz standard.

Let’s start with a simple chord progression:

Fig.1

So I guess the first question is: what key are we in? My guess would be C major (no sharps or flats), but since the phrase ends on an A minor chord, maybe it’s in A minor (the relative minor of C major). In a way it’s too early to tell—the phrase is too short. Let’s not worry about it; it’s one of the two, C major or A minor. First let’s look at the component notes of each chord (root position):

Fig.2 - Audio Example

Okay, these are all notes that are in the key of C major or A minor. How about if we voice the chords so they sound a little more musical:

Fig.3 - Audio Example

This voicing could become the beginning of our melody. If the chords are voiced in a way that sound good to you, with a voice-leading between each chord that make sense, then the melody almost begins to write itself.

Perhaps then the next step is to elaborate or add detail to the top voice, using passing tones, i.e. scale (or non-scale) notes that don’t belong to the chords but will lead from one chord tone to another. Using chord tones can also work. Let’s use a combination of both:

Fig.4 - Audio Example

Okay, a little dull, but it’s a beginning. Now let’s expand the chord progression out to 8 measures and vary the melody to (hopefully) make it more interesting:

Fig.5 - Audio Example

Well, in this case varying the melody meant making it simpler, because it was already starting to sound like a neo-classic hack piece. Now at least the line is more singable and a bit less self-conscious. Did I mention that having good taste is always helpful?

Notice that in measure 2 of Fig. 5, the first note is the non-chord tone C. Except that adding this C to the D minor chord effectively creates a D minor 7th chord. In measure 5 the first note is an E, which effectively creates an F major 7th chord, and with the addition of the D in measure 6, I now have an E minor 7th chord. So the use of melody notes that are not contained in the chord they are being used with actually expand the harmonic climate of that chord.

So, I’ve started with a harmonically simple chord progression and created a melody using chord tones, scale tones and passing tones, all strictly within the key signature. If we fast forward a couple of hundred years we can start to see how melodies can influence chord progressions, and vice-versa, by adding even more complicated intervals outside of conventional key signatures, scales and harmony. We enter the world of jazz, where scalic and chordal alterations are commonplace.

Fig.6 - Audio Example

(I’ve included a brief harmonic analysis of the melody so you can see more clearly how it works with the chords.)

Well, I think it’s in A minor now. You may have noticed that I’m still using the same basic chord progression (with some modifications), added a bass part, and spread the chords out a little bit rhythmically.

This article doesn’t even begin to address all the possibilities of melody writing based on chord progressions. We jumped straight from simple key-signature-notes-only chords to jazz-type altered chords. What about pop and rock style chord progressions, which are often modal in nature, or more modern styles where chords veer into the realm of diatonically un-classifiable?

Generally speaking, your approach would be similar—you’re using the chord progression as a foundation or outline to create your melody, so chord tones, passing tones that adhere to the scale or are chromatic, or tones that are a different scale superimposed over the key that you’re in are all fair game. Using notes that rhythmically anticipate an upcoming chord, or notes that hang on after one chord transitions into the next (a suspension) or common notes between chords are just the beginning of the many strategies that composers and songwriters use when they begin writing a melody based on a chord progression, whether they know that they are doing that or not. Ultimately, you have to let your ears make the final judgment.

Composer, guitarist and arranger Steve Kirk's music has been featured in film, video games and TV. This includes music for the Disney game version of "The Princess And The Frog", Microsoft Games "Voodoo Vince" , the FarmVille Theme for Zynga Games, and to be released in Spring 2011, Cantina music composed for the Star Wars MMOL game The Other Republic.

Steve teaches guitar, music theory and composition privately in Oakland, California, as well as Blue Bear School Of Music and Community Music Center- both located in San Francisco, California. He is also the guitarist for Club Foot Orchestra and Orchestra Nostalgico.