A young lady who is pretty incredible (she's one of those who only needs to hear a piece to play it and doesn't need to practice - *Sigh*). There's an article somewhere that talks about her synesthesia where she comments about the dominate colors she sees when playing certain composers. Pretty interesting!
There is one thing that I teach all actors I work with that has been extremelly valuable ... concentration!
And the physics axiom applies here without any Bapu'isms.
Quality is inversely proportional to Quantity!
I'm going to use the acting example as it is easier but you can substitute "lines" with "notes" easily.
You enter a new ______ and you have to learn 100 lines and you have to deliver them tomorrow ... it will define if you will enter this course or not in Advanced _______. You spend all night studying and trying to learn it all ... and when the time comes, you can do most of it ... and it's ... sloppy, but pass'able ... and in Advanced Acting, you would not pass ... because there are too many kids trying out, and many got it down ... and "knowing your lines" is important, regardless of it being music or acting!
Here is the dope on this ... 100% concentration ... it will take you an hour. At 50% concentration this will take you 4 to 5 to 6 hours. With the radio on in the background and talking to the wife, girlfriend or friends, and text'ing ... you will not have these lines up and ready when the time comes!
In the end, this is all I did when I was tutoring folks at UCSB ... I taught them to study "better" so they could enjjoy the rest of their time there, and still get good results. This worked really well with actors -- why? ... you spent more time fooling around in rehearsal ... and learning to expand the value of the words and sentences ... and figuring out where it feels better on the stage ... and the folks that do this? ... they usually are the most professional and the better actors ... they may not be perfect, but they will be READY and THERE when you are ready to work!
The color thing is good, but for someone that already sees color, David's process becomes an overload trying to change my colors ... and I enjoyed listening to a lot of it ... but it is ... difficult if you do not have the musical knowledge that he is expecting folks to have! I doubt that someone with less musical knowledge will be capable of doing this as easily as he makes it sound ... there is no "logic" in the root note when it comes to "color" ... the color sequence just moves along ... but he is not seeing that. I speak of this off my own inner movie ... and a lot of music for me is not just colors ... but a non-stop movie ... and that, you already know is TOO MANY DAMN COLORS! ... to simplify it to one color!
So you want to be good, and not have to practice that much? ... you have to teach yourself to concentrate! ... it's not hard ... all you gotta change is a t-shirt now and then or a pair of pants, and take a shower here and there ... the rest is easy!
One last detail ... part of this process requires that you also have some fun whilelearning ... and too much of the Perfect thing, is not capable of having fun with it ... so academic in the end, but then academic anything is so mathematically inclined, including music ... so I am not surprised!