Books with scales, arpeggios and technical exercises are merely a result of the 19th-Century academic approach to developing technique, when teachers tried to make machines out of people (Industrial Revolution). The idea was that, since the music of the Old Masters contains such formulas, vocabulary, we should know them all. Besides, in the 19th Century, many thought that scales, arpeggios, and technical studies were the REASON of a good technique. Fortunately, there were those (Chopin, for example) who realized that they are merely the RESULT. It's high-quality movement one shoud aim for. Without that, any of those exercises will make matters just worse. I would go as far as saying that they are not necessary for the talented and certainly not very helpful for the untalented.
Paul
Okay, this is the classic argument against technical studies. Very valid, I must say.
I just know this: I was raised on Hanon -- and only practiced it two minutes before a lesson to keep out of hot water -- so it did me no good because I wouldn't let it.
In conservatory, I had no option, because of jury exams, to get out of playing all scales, all kinds of arpeggios in all keys at all tempi, thirds, sixths, tenths, etc. For reference, I used Hanon on occasion. Did it help? Don't know, because I was working on beefy stuff from the standard repertoire at the same time. Maybe THAT built my technique alone.
Flash forward. Quit piano for years to build a profession. Returned five years ago to the piano with a vengeance. Reached the technical point where i had left off as a very young man. Disappointed because I felt I was on a plateau.
Found a great teacher. Royal Academy trained. He urged Pischna and Dohnanyi exercises for strength and independence. Just did 30 minutes daily for 8 months.
Result? Huge leap forward in technical command. Revisited old repertoire from student days (Chopin "Etudes," Rach 2nd concerto, etc., etc.) and found I was quickly doing with these works what I couldn't do in my younger years: i.e., finally playing things at tempo. Not half-tempo. Not slowing down for the grotty bits.
I know this is not scientific, but it has it's own logic. As I've written before here, dancers do daily "class," basic barre work (senseless repetition? Not if you concentrate as you repeat). Athletes of all stripes do strength and agility training. Why not pianists who use muscles, too?
Are there artists and athletes who don't need to train? Baseball players who never need batting practice? Yes, I'm sure there are.
But, as for pianists, I doubt there were many among the highest ranks who went through early childhood training without a strict technical regimen enforced on them by teachers. Is their incredible virtuosity the result of 10 and 12 hours a day working on technique along with repertoire?
We'll never know. But with just 30 minutes a day, my technique has improved markedly. My interpretations, that once were only in my head and not realizable through my fingers, are now evident with, I can only imagine, the more secure mechanism I have developed through technical exercises.