Which piano pitch is preferable, "concert" or "international"?
By all means the "international," because it will fit your piano to be used in conjunction with any other instrument, no matter whence it may come. Besides, the international pitch was decided upon as far back as 1859, in Paris, by a government commission, numbering among its members such men as Auber, Halévy, Berlioz, Meyerbeer, Rossini, Ambroise Thomas, and many physicists and army generals. You can easily infer from this that, in determining that the A in the second space of the treble staff should have 435 vibrations a second, all phases of music—vocal, instrumental, string, brass, wood, wind—have been duly considered.
The Well-Tempered Piano Scale
Is there really a difference of three-eighths of a tone between A-sharp and B-flat on the piano?
There is no difference on the piano. But acoustically there is a difference, over which, however, I would waste no time, since the evenly-tempered scale has been generally adopted, and every composition from Bach's time to the present day has been thought and written in it.
The "Colour" of Various Keys
Is it not a mistaken idea that any one particular key is more or less rich or melodious than another?
The effect of a tonality upon our hearing lies not in its signature (as even Beethoven seemed to believe) but in the vibration proportions. It is, therefore, irrelevant whether we play a piece upon a high-pitched piano in C, or upon a low-pitched piano in D flat. There are certain keys preferable to others for certain colours, but I fear that the preference is based not upon acoustic qualities but rather upon a fitness for the hand or voice. We apply the word "colour" as much to tone as the painters apply "tone" to colour, but I hardly think that anybody would speak of C major as representing black, or F major green.
[THE STUDENT'S AGE]
Starting a Child's Musical Training