I’ve hinted at these things before -that many folks expect an opera, for example, to be an over composed musical. That is something musically simple and direct and many times lovely is dressed up with “composerly” touches so its artlessness is lost. This is done to gain a degree of seriousness or creativity deemed necessary to be real “classical” music. In a sense over composing is part of the “crossover” category of classical music. There is also a large demand for the familiar music especially in the choral world, yet even here a level of sophistication is required.
Technically speaking over composing consists of unmotivated compositional features, rather than organic, occurring in a work including; dissonance, textures, orchestration, word painting, and form.
Over composing is unfortunate as many interesting works are thereby diminished. When I hear works of this type I just want to clean up all the gunk, that is, the unmotivated dissonance.
The decision to do such things can be direct, as in training and teachers (they do it so do you), and indirect such as the rules of the compositional profession itself (commissions and opportunities).
Why does this happen?
The return of the English style. For many over composers the basis of their work is the artless folk and popular song. Ralph Vaughn Williams and Holst and perhaps Rachmaninoff are their models whether they know it or not. These composers however knew how to get out of the way of their melodies.
The problem is that their imitators are just that — even when they add such new details as a beat box. Many claim Erik Satie as a precursor yet he is always a model of restraint perhaps because of his extensive training.
It has come to my attention that over composing problem is also related to training, opportunity, and outlook. This is especially true when song writers have the ambition to become composers. The fact is there is a whole category of vocal music (mostly choir) which demands song based composition. This requires a songwriter with a little composition training. So there is a demand for simple songs and choir arrangements. There is money here. So perhaps over composing is a way for such a song to sound unique. Sadly, no. The problem here is that the demand creates a success and this success gives a composer a false impression of ability. Continued experience in the same line can lead to laudable professionalism but not necessarily better or more interesting work.
My advice?
Know your tools: learn counterpoint. Study the masters. On the other hand one must earn a living.
Take a simple folk song as a melody, add as complex an accompaniment as you can so as to obscure said melody. Then start reducing the texture to its simplest basis. Find the point where balance is achieved.