350 APPENDIX. VI. 



If a dozen singing birds of different kinds 

 are heard in the same room, there is not any 

 disagreeable dissonance (which is not properly 

 resolved), either to my own ear, or to that of 

 others, on whose judgment on such a point I 

 can more rely. 



At the same time, as each bird is singing a 

 different song, it is extraordinary that what we 

 call harmony should not be perpetually violat- 

 ed, as we experience, in what is commonly 

 called a Dutch concert, when several tunes are 

 played together. 



The first requisite to make such sounds 

 agreeable to the ear is, that all the birds should 

 sing in the same key, which I am induced to be- 

 lieve that they do, from the following reasons. 



I have l6ng attended to the singing of birds, 

 but if I cannot have recourse to an instrument 

 very soon, I cannot carry the pitch of their 

 notes in my memory, even for a very short 

 time. 



1 therefore desired a very experienced harpsi- 

 chord-tuner (who told me he could recollect any 

 particular note which he happened to hear for 

 several hours), to mark down when he returned 

 home what he had observed on this head. 



I had lately received an account from him 

 of the following notes in different birds. 



