The musical progress of the children was quite remarkable.  Marianne, which was Nannerl’s real name, soon began to play very well indeed, while little Wolfgang hardly had to be told anything in music, for he seemed to know it already.  The father would write Minuets for the little girl to study; her tiny brother would learn them in half an hour.  Soon Wolfgang was able to compose his own Minuets.  Several have come down to us which he wrote when he was five years old; and they are quite perfect in form and style.

One day Father Mozart brought home Schachtner, the Court trumpeter, to dinner.  Coming suddenly into the living-room, they found the tiny elf busily writing at his father’s desk.

“Whatever are you doing, Wolferl?” cried his father, gazing at the ink stained fingers of his little son and then at the paper covered with blots.

“Oh, Papa, a piano sonata, but it isn’t finished yet.”

“Never mind that,” said Leopold Mozart, “let us see it, it must be something very fine.”  Taking up the paper the father and his friend looked at it curiously.  The sheets were bedaubed with ink stains that almost concealed the notes.  For the child had thrust his pen each time to the bottom of the ink well, so that frequent blots on the paper were the result.  These did not trouble him in the least, for he merely rubbed his hand over the offending blot and proceeded with his writing.

At first the two friends laughed heartily to see how the little composer had written the notes over smudges, but soon the father’s eyes filled with happy tears.

“Look, my dear Schachtner!” he cried.  “See how correct and orderly it all is, all written according to rule.  Only one could never play it for it seems to be too difficult.”

“But it’s a sonata, Papa, and one must practice it first, of course, but this is the way it should go.”

He sprang to the piano and began to play.  The small fingers could not master the more intricate parts, but gave sufficient idea of how he intended the piece to sound.

They stood in speechless astonishment at this proof of the child’s powers; then Leopold Mozart caught up the little composer and kissing him cried, “My Wolfgang, you will become a great musician.”

Wolfgang, not content with merely learning the piano, begged to study the violin also.  His violin lessons had hardly begun when one evening his father and two friends were about to play a set of six trios, composed by Wentzl, one of the players.  Wolfgang begged to be allowed to play the second violin.  Needless to say his request was refused.  At last he was told he might sit next to Schachtner and make believe play, though he must make no sound.

The playing began, when before long it was seen the boy was actually playing the second violin part and doing it correctly.  The second violin ceased bowing in amazement and allowed Wolfgang to go on alone.  After this he was permitted to play all the second violin part of the whole six pieces.  Emboldened by this success, he volunteered to attempt the first violin part, an offer which was greeted with laughter; but nothing daunted, he took up his violin and began.  There were mistakes here and there, of course, but he persisted to the end, to the astonishment of all.