octaves--struck with a strong staccato touch; and beware of playing too quick. In performing simple airs, which very few people can do fit to be listened to, study the _style_ of the different nations to which the tunes belong. Let any little grace be clearly and neatly executed, which is never done brilliantly or well by indifferent performers of a higher style of merit. Make proper pauses; and although you must be strictly accurate as to time, generally speaking, it should sometimes be relaxed to favor the expression of Irish and Scotch airs. Beware of being too sudden and abrupt in your _nationalities_--caricaturing them as it were--which ignorant and sometimes indeed scientific performers often do, totally spoiling by those "quips and cranks" what would otherwise be pleasing, and which sounds also to those who really understand the matter very ridiculous. Do not _alter_ national airs; play them simply, but as _full_ as you please, and vary the bass. In duets, communicate your several ideas of the proper expression to your fellow-performer, so that you may play into one another's hands--give and take, if I may so express myself; and should a mistake occur, do not pursue your own track, leaving your unfortunate companion in difficulties which will soon involve yourself; but cover it as well as you can, and the generality of listeners will perhaps never discover that one was made, while the more sapient few will give you the credit you deserve. As regards singing, practice two or three times a day, but at first not longer than ten minutes at a time, and let one of these times be before breakfast. Exercise the extremities of the voice, but do not dwell long upon those notes you touch with difficulty. Open the mouth at all times, in the higher notes especially, open it to the ears, as if smiling. Never dwell upon consonants. Be distinct from one note to another, yet carry them on glidingly. Never sing with the slightest cold or sore throat. Vocalize always upon A, and be careful to put no B's before it. Never take breath audibly. Begin to shake _slowly_ and steadily. Practice most where the _voce di petto_ and the _voce di gola_ join, so as to attain the art of making the one glide imperceptibly into the other. The greatest sin a singer can commit is to sing out of tune. Be clear, but not shrill; deep, but not coarse.