A Christmas-oriented WIP ... about one minute completed ... what do you think?

I'm afraid that's a rather broad question, actually. The short answer would be, 'yes, you can do that but you have to understand structure first in order to get away with it.'

In brief, almost every type of music has an underlying structure. High Baroque sonatas use the fast/slow/fast three-movement form for the most part. The two fast movements will often contain three sections, of which the middle one is a modulated variation (in the relative minor/major or the dominant, for instance) of the first theme, and the third section is a recap in the original key, often with virtuoso variations on the first theme to end the movement. The slow middle movement will be shorter--sometimes only two sections--and will likely be written in the relative minor (or major) of the principal key.

Classical symphonies are a bit more complex. They are generally structured in four movments, which will in turn be structured in one of a number of different ways--sonata-allegro design, song and trio design, theme and variations (possibly A-B-A or something similar, such as the fourth movement of the Eroica), a rondo.... Within each of these designs, sub-structural elements such as exposition, development, recapitulation, and coda, are fairly well defined, although it is up to the composer to define each element musically.

A study of music history shows that in highly complex works such as these, written by the major composers of the 17th, 18th, and 19th centuries, structure is derived from the work rather than vice-versa. One studies what the masters have done, analyses it, and puts salt on its tail, so to speak, in order to understand it better. For an excellent treatise on symphonic structure, try to find a copy of The Symphony and the Symphonic Poem (Earl V. Moore and Theodore E. Heger, Ulrich's Books, Ann Arbor (MI), 1962).

But 'popular' music is another animal entirely. Pop music is by design anything BUT complex, and it is extremely formulaic in both the harmonic and structural spheres. For reasons having as much to do with radio stations' playlist rotations (the infamous 'top forties') as with the limited attention span of the targeted listener, pop songs are generally limted to three minutes and are very, very strictly structured. First verse, chorus, second verse, bridge, third verse, chorus. Each section is almost invariably eight measures long--except for the bridge, which is sometimes only four measures--so total song length is 44-48 measures, and at 60 bpm in 4:4, that comes out to just under 3 minutes.

Why eight measures per verse or section? I don't have a definitive answer. Some 'music psychologists' claim it has something to do with the biorhythms inherent in human beings, but I'm not convinced. The practical answer is the usual one: 'Because it works.' Musical phrases that are eight measures long tend to satisfy uncritical listeners and stick in their memories, and sad to say, the great bulk of the music-buying public is fairly uncritical. If you keep each phrase to eight measures, and don't throw more than three or four chords at them--preferably I, IV, V, and possibly VI, if you're brave and good at what you're doing--you make it easy for them to absorb what you're saying. It's not high art, that's for sure. But that's where the money is, so if you want to write commercial music, learn the formula and stick to it.

Self-study--or 'autodidactism', if one wants to show off one's vocabulary--is good. I have dropped out of more colleges and universities than I care to admit, but education doesn't begin and end in those ivy-encrusted ivory towers, nor is it dependent upon a syllabus and a MWF class schedule. It is a continuous process that depends upon the learner's passion for his subject. This is particularly true in the arts. Art is never bound by rules; rather, it creates them without meaning to, after the fact...and those derived rules can then be used by 'ordinary' people in an attempt to understand how a great work of art came to be created, and why it is considered great.

I studied a lot of stuff in school that I didn't appreciate at the time--; and I will freely admit that I haven't thought much about the technical structure of a Classical symphony since Beethoven was a boy. But that early training provided a basis for understanding what later--and earlier--composers did, and why. Fifty years later, I can only thank those long-dead professors (most of whom I absolutely despised at the time!) for having force-fed me what I didn't know I needed to know. ;o)