Think of the chart as a musical instrument and the planets as musicians. Musicians make music according to their taste, but also according to the instruments they are given to work with. Take a musician and give her a piano; she will make a certain kind of song because the piano has 88 keys, etc. Give the same musician a guitar and she will make a different type of song, because the guitar has different properties than a piano. There are things you can do with a guitar that you can’t do with a piano.
To begin reading a chart you have to figure out what kind of “instrument” it is. You do this by carefully evaluating the rising sign and the essential modifications to that rising sign causes by the specific placements of the planets in the chart. You had to look at specific planets, yes – but only in so far as seeing how they modify the rising sign.
There are 12 rising signs, so you could say there are 12 categories of “instruments” that the planets can “make music” with. In any category there are lots of major and minor distinctions. Guitars, for example, are a general type of musical instrument. But there is a big difference between a hawaiian ukulele and an electric bass guitar, for example. And even among ukuleles there are different brands, qualities, tunings etc.
By examining the rising sign you understand the type of “instrument” the chart is. And then by reviewing the planetary placements in the chart, you get an idea of the subtype. From the rising sign you could say, for example, “OK this chart is a guitar.” And by examining the planets in relation to the rising sign you can figure out – “OK, this is an electric guitar in standard tuning.”
You still don’t know what music the musicians are going to make with this instrument! But you do know what they have to work with. If one of the musicians wants to make a flute quintet sonata… it’s not going to really come to pass, because an electric guitar just doesn’t support that sort of music.
So by evaluating the inherent, derived, and extended properties of the rising sign, you understand clearly the potentials of the chart. Next you will have to read the actual planets and see what sorts of “songs” they want to make. When they want to make songs that fit well on electric guitars, bingo! Big things happen. By first examining the rising sign thoroughly you know have done something very important: you have made your job as an astrologer possible! You now know what you should pay attention to and what things you can ignore. Or, to put it another way, you know which interpretations to make and which not to make. Your task has gone from an impossible amount of potential interpretations to a manageable and “possible” range.