Nor should the tempo be too slow. Slow movements are effective, but sufficient animation must prevail to impart life and fervency to the music. A stream may flow so sluggishly that the water loses its clearness. This is not repose, but stagnation. During the musical season of 1899-1900 in New York I heard modern pianists play some of Chopin's compositions so slowly that the effect produced upon me was like that of a music-box running down. One endures it for a while, but finally is wrought up to such a feeling of impatience as to induce the exclamation, "Either stop that thing altogether or wind it up." TEMPO RUBATO In modern times there is also a tendency to excessive use of tempo rubato. I have recently heard the second part, of Chopin's "C Sharp Minor Scherzo"--the choral with arpeggio passages--played by a celebrated pianist in such a way that, mathematically adjusted, about one measure was added to every section of four. The player was afterward highly extolled on account of his wonderful rubato effects. The truth is that he was all the while simply playing mathematically out of time. Rubato ("robbed") is a slight modification of rhythmic flow in alternation with a corresponding compensation; it is like excitement in verbal narrative; it is alternately losing and making up, but within judicious bounds, so that in the end the balance is preserved. The nature of music is essentially "tune and time"--in other words, emotion and intelligence, or heart and head, in loving and well-balanced combination. These conditions are absolute and can never be violated without disaster. Hence a true rubato must be played in time, but accommodatingly. UNUSUAL PUPILS--TRANSPOSING--POSITIVE AND RELATIVE PITCH I once gave to an intelligent pupil the task of transposing one of Bach's inventions into various keys. My directions were that at her next lesson she should be prepared to play it successively in three or four different keys. As she came to my studio for her lesson but once a month, there was ample time for preparation, and she succeeded in accomplishing the feat with ease and without error. But, more than this, she continued her transposing until she had completed the round of all the twelve keys without a mistake--a rare and creditable performance, deserving the emulation of all young ladies and gentlemen engaged in the study of musical development and the cultivation of pianoforte technic. Another case is that of a young lady pupil not remarkably musical, but who has an ear for positive pitch. By this is meant that she could immediately name the pitch of any tone on hearing it sung or played. All competent musicians possess the power of relative pitch. I mean by this that if a definite pitch is given to one who has a musical ear, the pitch of any other tone immediately following or sounding in connection will be instantly perceived, and the interval between the two tones--in other words, their pitch relationship--at once understood.