When Handel travelled through Chester, on his way to Ireland, this year, 1741 (to give the first performance of Messiah), I was at the Public School in that city and very well remember seeing him [Handel] smoke a pipe, over a dish of coffee, at the Exchange Coffee House; for being extremely curious to see so extraordinary a man, I watched him narrowly as long as he remained in Chester, which, on account of the wind being unfavourable for his embarking at Parkgate, was several days. During this time, he applied to Mr. Baker, the Organist, my first music master, to know whether there were any choirmen in the cathedral who could sing at sight, as he wished to prove some books that had been hastily transcribed, by trying the choruses which he intended to perform in Ireland. Mr. Baker mentioned some of the most likely singers then in Chester, and, among the rest, a printer the name of Janson, who had a good bass voice and was one of the best musicians in the choir…

A time was fixed for this private rehearsal at the Golden Falcon, where Handel was quartered; but, alas! on trial of the chorus in the Messiah, 'And with his stripes we are healed,' poor Janson, after repeated attempts, failed so egregiously, that Handel let loose his great bear upon him; and after swearing in four or five languages, cried out in broken English,

Handel : "You shcauntrel [scoundrel]! tit not you dell me dat you could
               sing at soite [sight]?"
Janson : "Yes, sir, and so I can, but not at first sight."

Charles Burney, An Account of the Musical Performances…in Commemoration of Handel (1785).  Cited at: gfhandel.org,  Accessed 1 May 2010.