I know I am stepping into this conversation late.
My feel on whether everyone suffers endless hours of practice to play a specific tune is this… yes. Even the most talented folks still put their time in.
However, as a teacher, I have noticed that some students have an uncommon ability to learn new material quickly while others struggle with the simplest techniques. There can be all manner of reasons for these differences; one person may have a better memory, or physical coordination, or musical ear, while the rest of us have average (or in my case, less than average coordination and memory) skills in these areas.
So it is true that all good/great players spend serious time on their instrument. I believe, as you grow as a musician, your basic skill level is high enough for you to learn a new tune “possibly” faster than someone with less years on their instrument. I have also found that some amazing musicians have a difficult with some techniques that nearly beginning musicians can handle easily. For example, I was teaching a violinist from the Philly Orchestra to learn to improvise. This woman had no idea how to use her skills in that manner and the concept was completely foreign to her. While even beginners, if you give them a scale pattern, can bang out a simple improvisation with out much difficulty.
So some folks learn by ear, some folks learn by note reading, some folks learn by rote and some folks learn by some combination of the three. It has been extremely important to me (as a musician) to know what I am doing at any given moment. That means that I want to know WHY certain runs and notes sound good together over a given harmony. While some of the greatest bluegrass guitarists have never given a thought to such nonsense. The greats that I have had the pleasure to meet, often learn by ear and rote and never give a thought as to why this certain set of notes sounds better than that certain set of notes… they just know it sounds better and that is what they are looking for.
Unfortunately for me, my memory is not all that good and I cannot remember a good sounding riff much longer than the current practice session. The only way I can repeat such a riff is to know WHY is sounded good and apply that knowledge in the future to similar situations (a very long way to go to play a riff)
So, as this excessively long post has tried to point out, we all have our burdens in the process to learn music. Some very talented individuals can learn more quickly based on their strengths as a learner (memory, reading, physical coordination, ear for music…etc). Some of us (most of us) struggle with the process of learning. However, as we complete work on a well played tune, the payoff to ourselves is huge. And that is why I took up the guitar; not because it was easy to play, but because it required me to really work hard for everything I learned.
As Daryl Van Horne (Jack Nicholson playing the devil in the Witches of Eastwick) said about playing the violin, “Music…It’s the one thing that keeps me humble.”
But it sure feels good when you get it right occasionally.