How much of a composers skill is born with them?

Another example could be Modest Mussorgsky whose music was for long time known only in version ironed out by more classically trained composers from 'the Five' group.

None of the Five had any real formal training though. They were all pretty much hobby-composers next to their diverse day jobs. When they started out there -wasn't- even such a thing as a formal classical music training in Russia. (It was only just starting to come up at that time.)

And John Cage studied with Sch

That is true, John Cage has studied with Sch

Well, this line of question is pretty moot in my opinion. Fame in the musical world has little to nothing to do with actual musical ability honestly. It's wishful thinking to think that those with actual ability, those that deserve recognition, will find it.

Another point I just thought of, if music is something that is inherited through genetics, how can you explain composers who have drastic stylistic changes throughout their career? Scriabin is a great example of this, I think. A lot of his earlier works are just derivative Chopin in my opinion. Little in the way of interest and entirely pastiche. I wouldn't say there is much "talent" evident in his early compositions other than obviously have a good understanding of keyboard technique. Over time, his style began to become a little more idiosyncratic with more unresolved dissonances, rhythmic complexity, and unprepared modulations happening. This newer voice manifested itself most effectively in the 5th piano sonata, I'd say, which stretches functional tonality to its very limit. It would make sense had Scriabin continued cultivating this musical voice throughout his career however, this was not the case. Immediately after the 5th sonata, Scriabin's music takes a drastic turn to the Poem of Fire. As dissonant and unrestrained as the 5th sonata is, it still remains ultimately tonal and logical in continuation of the Romantic era. The Poem of Fire, on the other hand, is entirely removed from anything even resembling Romanticism. After this piece, Scriabin's style changed almost entirely (though still with enough quirks to still be definitively Scriabin) being based largely around the octatonic mode and quartal harmony. I personally believe some of Scriabin's late pieces are some of the most imaginative and ridiculously forward thinking pieces in all of music in terms of historical context (along with Ives and Varese).

So, my question is, if Scriabin was "born" with any kind of musical cognition/talent, then why did it not show itself until well into his 30s? And another, perhaps more important question, when we speak of "talent", can it be specialized to certain styles/areas of music or must it always just be a general ability? Can it be both?

but my point here is that he studied only after he started composing.

Well, that is probably the case with most composers. You don't generally start taking composition lessons unless you're either:

1. Forced to (generally by your parents). I don't think that's as common as being forced to play the recorder/piano/whatever though.

2. Start inventing your own music, trying to write it down and discovering an interest for it.

In all the latter cases, composers already were composing before they received formal lessons. And I'm sure this applies to the majority of people on this forum too.

My two cents: [WARNING- long post]

-How much of a composer's future skill is with them when there born (not that they are a skilled composer at the age of 1 week, but that they are going to begin to compose at a very early age and at very high quality).

Well, there's no denying that people are born with different abilities, and there can be a lot of variation even within families. People are born with better and worse ears, more and less creative drives, and so forth, just like people can be born with more or less athletic builds, better and worse color perception, ability to tolerate spicy food, etc. So, of course, some composers were born with a huge amount of innate musical ability and began composing as small children.

However, we can't extrapolate from this that composing is all about innate ability. To drag out a tired example, Mozart was a child prodigy- who was also intensively trained by his somewhat abusive father. Anyone who receives intensive daily musical/compositional training from the age of three is going to be able to write something when he's eight. Of course, Mozart had a high degree of musicality and had the ability to come up with good tunes- I'm not saying he was entirely the product of training. But we can't discount training and family environment when examining the life of anyone, composers included.

Let's take a theoretical example: we have two six-year olds, Garrett and Michael. They are given an aptitude test at school and have identical scores in all areas. Garrett's family has been in the armed forces for as long as anyone can remember, while Michael's parents are writers. So in this artificial scenario, we have two boys with identical musical aptitude, but with radically different home lives.

Garrett has never receieved any musical instruction. He sings in the shower sometimes, and his family will sing along to a CD on a car trip, but they are not especially musical or artistic. Garrett hears a symphony on the radio somewhere and starts listening to classical music. He starts figuring out how to write down his own musical ideas. After a while he asks his parents for violin lessons and shows them his tunes. Though they love him to death, they don't think that music is where a red-blooded American boy belongs, unless maybe he wants to be a rock star and play the electric guitar. His parents, acting purely out of love, tell him that he should play football instead. Garrett is crushed and, in an attempt to please his parents, gives up writing music and goes in to sports. He joins the Marines when he graduates high school and doesn't venture in to composing again until he's honorably discharged at 30.

Michael's musical exposure is initially the same as Garrett's. He hears the same symphony as Garrett and also starts trying to write his own tunes. He asks his parents for violin lessons the same day Garrett asks for his, and shows his parents his works. Being arty types, they sign Michael up for violin lessons and a music theory class. Michael's first quartet is published when he's 16, after ten years of hard work.

This isn't a perfect example, but I think it does a decent job of illustrating my point: aptitude is nothing without the right environment. Also, composing at a young age is not necessarily an indication of early compositional skill. Some prodigies may be able to write music from a very young age but never develop an interesting voice. Some people may be naturally very self-censoring and therefore not develop their compositional interests until a later age, despite a lifelong interest.

So, in conclusion, people are born with certain degrees of aptitude- but aptitude is far from everything.

-How much of a composer's skill comes from just hearing other music and studying music?

This is a weirdly-worded question. There's a big difference between hearing music and studying it.

Composers absorb their musical language from the cultures around them. This is why people who have been raised solely on, say, Indian ragas, will not spontaneously write a Haydn-style string quartet. (Likewise, someone raised on Western classical music will not bust out an Indian raga out of nowhere.) A composer learns about music through listening to it- you music listen to a lot of music to be a good composer. I would venture that the majority of a composer's skill comes from studying music...studying music is how you learn to put your random musical ideas together in to a coherent work. A symphony's theme has to be powerful, but what carries the bulk the emotional effect? The exposition of that theme and everything else a composer does during the course of a symphony. Studying music helps you improve your musical communication. (Of course a symphony's theme is important, but try just listening to the opening theme of any symphony and nothing else. Maybe then my point will be clearer.) Anyone can come up with a tune, but it takes musical training to learn what to do with it.

Sorry, but the wording of this question put me off a bit. It seems a bit like asking how much of a doctor's skill comes from attending medical school.

-Can a person start composing at a very high proficiency level when they're ol without having any previous training or even a thought about music and is there anyone out there who did this?

Can a person start performing brain surgery at a very high proficiency level when they're old, without having any previous training or even a thought about medicine?

Someone who never cared about music, was never interested, never immersed herself in it, is not going to have a modern St. Matthew Passion pop out of her head. Often people who say they haven't had musical training aren't being quite honest. They don't count the years they spent as active members in their church choir, school band, etc. "I fooled around with a guitar when I was a kid, and played in a band in college, but I never really had any musical training," isn't uncommonly heard and, IMHO, completely false. If you played guitar and wrote some songs, you had musical training and you composed. Were you trained by people who had fancy pieces of paper, and given a fancy piece of paper to prove you were trained? No, but you still learned about music.

Proficiency is gained through practice. A child piano prodigy spends several hours a day playing piano. Yes, his brain is wired so that he will learn faster than the average child his age, but it's not like he practices for 20 minutes a day and then goes and plays in the mud like most other kids. Mozart's first works, taken on their own and not as the creative output of a third-grader, aren't anything special. When he was 14, after he'd been working on music for a decade, he was turning out really good stuff. It takes 10,000 hours of concentrated effort to become a master at anything. There are no shortcuts.

My sources are This Is Your Brain on Music by Daniel J Levitin, a few Teaching Company lectures by Robert Greenberg, and a lot of other reading I can't cite.

Can a person start performing brain surgery at a very high proficiency level when they're old, without having any previous training or even a thought about medicine?

I agree with several of your points, but I don't think the comparison you're making here works. Being a doctor is a job with rather clearly defined standards and measurements of success. If the patient dies, it's a bad result. If you heal her/him, it's a good result.

In the arts, no such criteria exist (at least not today). There's no clear way of telling whether a composition has succeeded or not, and no real way of telling whether a composer is "good" at what (s)he does or not. "Mastery", in composition, isn't defined.

Furthermore, composing is always only as hard as you make it for yourself. You can set yourself a task you know you can easily accomplish, no matter how "advanced" you are - or you give yourself a huge challenge and set very demanding standards for yourself. Again, neither of those approaches will guarantee you a "good piece" (even though I -do- appreciate it when composers set high standards for themselves) - in the end it's a personal decision.

There are plenty of composers with a ton of knowledge and working ability in established processes of composition who still never manage to write anything that even remotely interests me. And then there are random people who start to compose very late in their life, coming from entirely different fields, who write totally awesome stuff.

Of course, that doesn't mean that most of the latter don't also work and study very hard for their stuff. But there's really no set of requirements of how long and how intensively you have to study to become a "good composer".