Tonality is no longer what it once was. Today, songs can start in one key and end in another. The transposition of a section by consecutive upward moving semi-tones is a pervasive feature of popular music. These transpositions, as opposed to modulations, are a technique from serial music.
Harmony:
In jazz harmony as well as Rameau’s (Baroque) harmony, triads (3 note chords) no longer rule. These triads are expanded. Chords are stacked to become 7th, 9th, and 11th chords. Frequently these chords omit the 3rd and the 5th of the chord. Songs no longer end with a tonic triad, but may be a 9th or at least a Major 7th chord.
Leading Tone:
If you remember your solfège, a diatonic scale goes Do-Re-Mi-Fa-Sol-La-Ti -Do. “Ti” is the leading tone of the scale bringing us back to “Do” — but popular music tends to omit the leading tone. A study of the music of Laura Nyro would be instructive. A typical cadence is V7 to I, but in Laura Nyro’s music a cadence is described in C major as an F/G in the bass (an F major triad with a G in the bass—G-F-A-C). This could be related to an 11th chord with an omitted 3rd and 5th, G-omitted b-d-F-A-C. Which ever way you look the leading tone is gone.
Ms. Nyro’s music suggests a pan-diatonicism, which is the term the Arnold Schoenberg used to describe his own non-tonal music. In addition you can freely add to a major scale chord’s formations, notes from its related pentatonic scales. In C major: Major C-D-E G-A Minor C D Eb F-G Bb and add the Blue note F# — notice that the leading tone is also absent from these scales. The bass motion in these progressions remains the same as traditional harmony, but in popular music the bass can freely improvise over harmonic patterns which becomes strongly accented by use of the electric bass.
Examples: To a tonic triad –CEG — and D, or and Eb, or add A.
Resolution of Dissonance:
In popular music dissonance no longer has to be resolved at all. This is because dissonance becomes part of the harmonic formation. For example in a C major a tonic triad (C-E-G) the note A (not a member of the triad) would resolve by step down to G, a triad member. Today the note would stay as part of the chord formation, no longer being resolved. On the other hand, the note F frequently does resolve to E in C major. This resolution is a main feature of popular music.
Dance Stuff-Electronics:
Since the dance beat is primary most anything you add on top of the primal beat will work. Different expressions of the beat pattern can be mixed together, collided against each other, or used as a way to introduce a new pattern. It is common for DJ’s to mix different songs (loops) in different keys at the same time — as long as their BPM beats per minute match up. I have already mentioned that the segues between songs are dissonant. The only limitations here are the confines of the dance itself. For example, the dance version of “Mission Impossible” was in 4/4 time when the original was in 5/4 time (3+2). The dance requires groupings of even beats. I suggest trying loops of contrasting tension and contrasting styles, classical, country, western, funk, anything. Or, try related BPM’s 100, 50, 66.6, etc
A false sense of tonality:
Consonance in and of itself does not guarantee tonality. This is because tonality is more than just the “harmony” or the use of pleasant sounds. Tonality is made up of many reciprocating parts such as; rhythm, meter, motives, phrases, harmony, form, dynamics, etc. As in my “style-a-matic 2000” to alter any one of these aspects while still retaining many other tonal features still changes everything. Through these transformations we move into new musical realms — that is experimentation and the atonal.
It doesn’t really matter that many composers and their supporters believe that their favorite works are tonal when they “ain’t.“ One wonders why the word atonal is so disparaged by composers these days. One hopes its not because tonality sells, and sells big!