Endeavour to play easy pieces well and with elegance; that is better than to play difficult pieces badly.
Take care always to have your instrument well tuned.
It is not only necessary that you should be able to play your pieces on the instrument, but you should also be able to hum the air without the piano. Strengthen your imagination so, that you may not only retain the melody of a composition, but even the harmony which belongs to it.
Endeavour, even with a poor voice, to sing at first sight without the aid of the instrument; by these means your ear for music will constantly improve: but in case you are endowed with a good voice, do not hesitate a moment to cultivate it; considering it at the same time as the most valuable gift which heaven has granted you!
You must be able to understand a piece of music upon paper.