Whenever you talk about waveforms -- whether in music, science, mathematics, or here in astrology -- the idea of "harmonics" inevitably crops up. They are a universal way of describing the shape and form of a wave, or of talking about the various kinds of energies that blend together to form that wave. Each harmonic is a different kind of energy and they can mix together to create very complex patterns. In music, the mixture of harmonics in a sound determine the "tone" or "color" of that sound, making it possible to tell a flute from a violin. In astrology, these harmonics correspond to the common idea of aspects, the various ways that planets can combine their energies, even though they lie in different parts of the zodiac.
Harmonics in the A5 Spectrum waveform can be recognized by looking for a group of tall peaks in the graph that are evenly spaced in the horizontal direction (i.e., evenly spaced around the zodiac). The number of peaks in the group is called the "harmonic number" for that harmonic. For instance, a group of 6 peaks is called a "6th harmonic pattern", which I generally abbreviate as H6. Most waveforms are a mixture of harmonics, indicating a combination of different kinds of energy at work simultaneously. Some examples of harmonics in real-life waveforms should make this idea more clear.
H4 is simply a shorthand way of saying "4th harmonic" and H6 means "6th harmonic". In general, for any number n, Hn stands for the nth harmonic. It saves typing and reading...
When talking about a waveform, I sometimes list a number of harmonics in a row. This means that all those harmonic patterns are present in the waveform, in varying degrees. The list of harmonics is always ordered from most to least important. The more important harmonics that are first on the list describe the overall "color" or mood of the energy represented by the waveform, while the less important ones produce variations on this main theme (the "spin control", so to speak).
Once you've determined the list of harmonics for a waveform, you need to "decode" the list. The most important harmonic or two describe the main "color" of the waveform energy; the rest of the harmonics fill in the details. Using the keywords for each harmonic, you can get a sense of whether it's easy/difficult, positive/negative, etc. By combining these descriptions in your mind, the overall nature of the energy emerges.
It's important to look at which planets "lie under the peaks" (the planet is near the zodiac position of the peaks for the harmonic) of major harmonics of a waveform. These are the planets that are creating the energy in the first place, so they tend to modify the keyword descriptions (below). You'll also find that these planets under the peaks frequently form powerful "complexes" or planetary patterns, such as T-Squares, Grand Trines or other fan-shaped groupings. It's this ability of the A5 Spectrum to find such complexes quickly and painlessly that makes it such a useful technique.
H1: A concentration of effort or attention in one direction; other areas neglected, underdeveloped, unconscious.
H2: Awareness of conflicts, disagreements, duality; caught between competing allegiances or courses of action.
H3: Easy-going, effortless blending of energy; achieves results without paying the cost; optimistic, but lazy.
H4: Conflict, testing, a clash of differing points of view; stress, resistance, opposition from others; incredible energy that needs a useful outlet -- don't let it stay bottled up!
H5: Creative change and insight; creative mental activity; overcoming problems by rising to a higher level.
H6: Upbeat, optimistic, productive if you put in the effort; easy-going, full of drive.
H7: Inwardly directed, "psychological" influence; subtle, hard to be conscious of it.
H8: Conflict, aggravation, things just get in the way; stressful, irritating; mix-ups and nuisances, things don't work out well; need to take things slowly and carefully, don't try to force issues.
H12: Constructive, easy-going, helpful; useful energy that can be worked with, but requires some effort and compromise; peaceful, pleasant, supportive.
H24: Agitated, stressful, irritating, friction; nervous, somewhat static-y, ungrounded energy; edgy, dynamic, driven; lots of energy, if you know how to use it skillfully; disharmony between two competing complexes.
H36: Fat, dumb, and happy; unconscious and unfocused; pleasurable, easy-going, non-taxing, laid back.
H48: Static-y, scattered, draining, distracting; highly changable situations that scatter concentration; unconscious mostly; very stressful physically.