Use of definite article before occupation

Question

I often see the definite article being omitted in texts about famous people. For instance:

Towards the end of his life, avant garde composer John Cage turned to visual art

But I also see that it is equally frequently not omitted:

In 1944 the avant-garde composer John Cage wrote “Four Walls,” a 70-minute work using only the white keys of the piano

I am assuming that these are both valid. But why would you choose one over another? Is version 1 more "written" and version 2 more oral?

Edit: note that googling "by the avant garde composer John Cage" yields 3150 results and "by avant garde composer John Cage" yield 3760, so it's kind of inconclusive to say which is more common.

Answer 1

In the first sentence, John Cage moves from being 'avant garde composer' to 'turned to visual art'. Quite logically (I think) the description is applied to the man more loosely (that is, without the article) because the sense of the sentence is that said description is being weakened.

He is no longer just a composer, he is now also a visual artist.

In the second case, 'avant garde composer' defines the man John Cage who wrote the Four Walls composition. Therefore the definite article.

Answer 2

Well, the question was

But why would you choose one over another?

The general answer would be "for the same reasons as always with articles in English". That is, to communicate something.

Let's consider these chunks.
1. sailor Tom
2. Tom, the sailor

The second example implies that there might be another Tom, say, being a writer, with whom the sailor Tom should not be confused.

As mentioned in the other answer by Nigel J, your example is also "exact person vs title" emphasis case. And, as you can read following the link in the KarlG's comment, this also a matter of how to use false titles.