[Sounds based on] time variation

Many systems discussed in this book produce sounds with distinctive and sometimes pleasing time variation. Particularly dramatic are the concatenation systems discussed on page 913, as well as successive rows in nested patterns such as Flatten[IntegerDigits[NestList[BitXor[#, 2 #] &, 1, 500], 2]] and sequences based on numbers such as Flatten[Table[If[GCD[i, j]  0, 1, 0], {i, 1000}, {j, i}]] (see page 613). The recursive sequences on page 130 yield sounds reminiscent of many natural systems.