This is the first part of a series of articles about music ideals.

If you ask people at random "why do you listen to music?" the range of answers will vary a great deal.
The majority will probably answer "because it makes me feel good", implying an emotional satisfaction derived from the act of listening.
Other, maybe more refined listeners will answer "because it has beauty", the return here being one that belongs to the aesthetical domain.
Other people listen to music because it helps them concentrate while working, yet other people will utilize music to relax after a stressfull day, or perhaps to help alleviating certain ailments. In other cases music is a support for social activities (think about the carnival at Rio de Janeiro) while some other times the society uses music simply as a tool to put its member to work to accomplish certain goals (like the military music used to create a certain state of mind in soldiers). Also, music can be simply a decorative element, like when soft music is played in the background at various exhibitions or in restaurants or other public places.

In order to find the common thread to all these various situations, we have to look at how the music interacts with the listener.

Certain types of music seem to influence the listener directly at the physical level. The typical example of this kind of music is the african traditional music, but also certain parts of the asian tradition and in isolated instances in the european tradition; in general all other kinds of music where rhythm is the dominant part (the modern dance music, etc.) fall into this category. The listener typically describes the perception of this music as happening "inside the body", usually pointing to the arms, feet or abdomen as the areas which seem to respond the most. The muscular reaction can be quite powerful, which is why a strong rhythmic part is a trait of any kind of music that's created for dancing.
In certain rare and unusual circumstances, strong and monotonous rhythms are used to induce a kind of trance to those who participate - the listeners are drawn into a sort of hypnotic state whose features are usually related to elements of the culture which produces that particular kind of music. In such states, the rational mind seems to recede from the front of the consciousness and the individual responds more or less automatically, or seems to "load up" a kind of "program" and run it until the trance fades out.
Basic instinctual responses are stimulated by this type of music: aggression, sex, belonging to a group (the "herd response") and so on.
In any case, the music with a strong rhythmic section seems to hook up to the lower stages of the brain, the ones in direct connection with the functioning of the body, the so-called reptilian brain (old strata of the brain containing the mesencephalon, the pons, etc.). This explains the common and widespread feeling that this music interacts primarily with the physical level, and also explains the non-rationality of the state of mind in those extreme and rare cases where rhythms are used to induce trance.

Other kinds of music seem to primarily target emotions. This is true, for example (but not exclusively) for many traditions in the european and asian cultural space, practically including most of the folk music and traditional music in these parts of the world; parts of the european classic ("educated") music are included, and so are some corresponding "educated" types of music originating in parts of Asia, such as parts of the hindu "classic" music. Some african folk music falls into this category as well (traditional choruses).
The listeners describe it as music that "speaks to the heart". Projecting it to the body is rare but, when it happens, the chest is the preferred area.
It is typical for this music that the lyrics (if it has lyrics) tend to dwell upon things that touch the listeners emotionally; love, sorrow, happiness, longing - all of them are preferred themes to this kind of lyrics.
The extreme cases are those when listeners manifest strong and sometimes violent emotional reactions to the music. It is not a thing unheard of that such music makes people, given special circumstances, cry.
It is obvious that this type of music connects primarily to the part of the consciousness that contains the emotional activity - the so-called limbic system or the old mammalian brain, right under and slightly older and more primitive than the neocortex. In any case, as a result, it's the emotional part of the consciousness that's primarily influenced here.

Finally, there are kinds of music that are better listened to "with the mind". At the lower end of this spectrum, this music is described as "beautiful", hence touching the listeners in an aesthetically-pleasing fashion - and it almost crosses the border down towards the kind of music previously described, the "emotional music". At the higher end, it is a truly "intellectual music", that makes the listeners active in the rational parts of their minds.
This is the case with the most sophisticated parts of musical traditions all over the world. It is also the case with new developments such as parts of the "electronic music" current, as an example.
It is obviously a music that touches the "thinking machine" inside the listeners' consciousness. If you look at the body language when people talk about it it almost never has a physical projection, except in some cases when the listeners point to their heads to emphasize the intellectual content of the music. It probably involves the neocortex, which is the most recent and complex part of the brain, the brain of the advanced primates and of Homo Sapiens.
The reactions to this music are extremely diverse, like anything originating in the neocortex. It is hard to find a behavioral common thread here.

Physical music, emotional music, intellectual music. Three different targets, but one common background: it's always the consciousness, or parts of it, that's affected by music. People are influenced by music because music affects the consciousness.
Now, different people react in different ways to music, and also different people are living focused on different parts of their brains/minds. Someone whose instinctual brain ("reptilian" brain) is energized and highly active will naturally hook up more easily to music with a strong rhythm. Someone else who has a very strong limbic system ("old mammalian" brain) and therefore lives a life with strong and colorful emotions will feel attracted by the emotional music. Finally, someone who has most of the brain energy focused in the neocortex will tend to pay more attention to the intellectual type of music.

It probably goes without saying that, in actual fact, any given musical composition does not fall clear and strictly into one of the three categories asserted above. Often, songs appear to lean closer to one category, or maybe two. But even those songs who seem to fit a category's description very strictly usually possess elements of at least one other category.
Also, people do not belong to three different and strictly divided classes. We're talking here about general tendencies and we're cutting off a lot of details to simplify the discussion.

What all this means to musicians?
There are probably many conclusions to be drawn, however, we cannot analyse them or just mention most of them. I'll go directly to the core: in order to reach as wide an audience as possible, the composer will probably have to diversify the music, including elements from all three categories into the work.
Including "physical" (rhythmical) elements will make the music interact with the listeners in an immediate, concrete, physical fashion. Including emotional content will make people hook up to the music emotionally. And including complex, intellectual elements will give people's brains (actually, only the neocortex) something to relate to.

The "perfect" music is bound to be a total music, one that interacts with the listener in many different ways. It ought to be a music that delivers a rich message, so that the entire being, body, heart and brain, is touched and involved. It must be a complex music, that can be "seen" on many levels and continues to provide significance regardless of the angle of view.

Target the whole, and there will be reactions everywhere. That's how perfect, ideal music should be.