[ 6i. ] 
The word he pitched upon for this fecond extem- 
porary compofition was, Pcrfido. 
After this he played a difficult leffon, which 
he had finiffied a day or two before *: his execution 
was amazing, confidering that his little fingers could 
fcarcely reach a fifth on the harpfichord. 
His afionifking readinefs, however, did not arife 
merely from great pradice ; he had a thorough 
knowledge of the fundamental principles of compo- 
fition, as, upon producing a treble, he immediately 
wrote a bale under it, which, when tried, had a very 
good effed. 
He was alfo a great mafier of modulation, and his 
tranfitions from one key to another were exceffively 
natural and judicious he pradifed in this manner 
for a confiderable time with an handkerchief over 
the keys of the harpfichord. 
The fadls which 1 have been mentioning I was 
myfelf an eye witnefs of; to which I muff: add, that 
1 have been informed by two or three able mufi- 
cians, when Bach the celebrated compofer had be- 
gun a fugue and left off abruptly, that little Mozart 
* He publifhed fix fonatas for the harpfichord, with an ac- 
companiment for the violin, or German flute, which are fold 
by R.Bremner, in the Strand, and are intituled, Oeuvre Troif mc . 
He is faid in the title page to have been only eight years of 
age when he compofed tiiefe fonatas. 
The dedication is to the Queen, and is dated at London,. 
January 8, 17,65. 
He fubfcribes himfelf, “ tres humble, et tres obeiifant petit. 
M fervitcur.” 
Thefe leflbns are compofed in a very'original fiile, and fome 
of them are mafic rly. 
hath. 
