As luck would have it, while I was listening to a podcast of "The Story" called Hellbender and Vipers, Paul Auerbach let this phrase drop while talking about being able to recognize the physical signs of a person having been struck by lightning. His book, Wilderness Medicine, sounds fascinating.
I committed the phrase to memory (no easy task for me), mused upon it, and found out, after I returned home and consulted the oracle (the internet), that it is actually a common English translation of a statement made in 1854 by Louis Pasteur, "Dans les champs de l'observation le hasard ne favorise que les esprits préparés." In other words (and I mean that literally), that use of the word "luck" seems to be a comment on an entirely different matter.
What we call "luck" happens, I guess, because most of us interact with our environments, both in our day-to-day walking lives and through media. I can read a little French, so I am able to understand that Pasteur was talking about things that are possible to miss if you are not aware of the possibilities that may be right in front of your eyes. I would not say that it's lucky I took French in high school (something that did make it possible for me to read Pasteur's statement in his own words), but I would say that it is fortunate that I have been able to remember some the French that I did happen to learn. I would not say that it's lucky that I happened to be listening to that particular podcast, thus making it possible for me to write this blog post (what would Pasteur, I wonder, make of this sentence?), but I would say that it is fortunate that I noticed one particular phrase, and was able to amuse myself (and you) by thinking about it.
So what does this have to do with music? Practically it means that if I practice and remain in good playing shape, I will be able to make the most of any musical situation. Intellectually it means that I am able to recognize the way standard techniques are used by really great composers, and can compare the use of those techniques in the works of composers who were (or are) not as great. I can learn from the examples of excellence that we have in our vast musical repertoire, and begin to understand why some composers are/were more successful than other composers (independent of achieving fame or money). If, while writing a piece of music, I happen to write a note I didn't intend to write, and it ends up changing the whole direction or feeling of a phrase, I guess I would call that a case of luck favoring a mind prepared to explore all options.
If I come across a new piece of music that I love, I do consider it a bit of luck. A person without my particular set of musical experiences might not be able to recognize its exceptional qualities (I have also noticed that there are people who really don't care about stuff that interests me). There are also a whole lot of musical experiences embedded (or sometimes hidden) in pieces of music that I know really well. It is important to always keep our ears and eyes wide open, and ready for the next musical experience to reveal itself. Perhaps my version of Pasteur's statement would be that music favors the prepared mind.