368 THE LAW OF EVOLUTION CONTINUED. 



melody to harmony could take place without a sudden leap, 

 it is none the less true that it did so. The circumstance 

 which prepared the way for it, was the employment of two 

 choirs singing alternately the same air. Afterwards it be- 

 came the practice (very possibly first suggested by a mis- 

 take) for the second choir to commence before the first had 

 ceased ; thus producing a fugue. With the simple airs then 

 in use, a partially harmonious fugue might not improbably 

 thus result; and a very partially harmonious fugue satisfied 

 the ears of that age, as we know from still preserved exam- 

 ples. The idea having once been given, the composing of 

 airs productive of f ugal harmony would naturally grow up ; 

 as in some way it did grow up out of this alternate choir- 

 singing. And from the fugue to concerted music of 

 two, three, four, and more parts, the transition was 

 easy. Without pointing out in detail the increas- 



ing complexity that resulted from introducing notes of 

 various lengths, from the multiplication of keys, from the 

 use of accidentals, from varieties of time, from modula- 

 tions and so forth, it needs but to contrast music as it is, 

 with music as it was, to see how immense is the increase of 

 heterogeneity. We see this if, looking at music in its ensem- 

 ble, we enumerate its many different genera and species if 

 we consider the divisions into vocal, instrumental, and 

 mixed ; and their subdivisions into music for different voices 

 and different instruments if we observe the many forms of 

 sacred music, from the simple hymn, the chant, the canon, 

 motet, anthem, &c., up to the oratorio; and the still more 

 numerous forms of secular music, from the ballad up to the 

 serenata, from the instrumental solo up to the symphony. 

 Again, the same truth is seen on comparing any one sample 

 of aboriginal music with a sample of modern music even 

 an ordinary song for the piano; which we find to be rela- 

 tively highly heterogeneous, not only in respect of the 

 varieties in the pitch and in the length of the notes, the num- 

 ber of different notes sounding at the same instant in com- 



