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Table 23.2 The frequencies that the Mark II was able to
play by means of loops containing four-beat instructions or
mixtures of four- and five-beat instructions, down to the lowest
frequency in the BBC recording. By increasing the number of
beats in a loop still further, the machine will play ever lower
notes, until at approximately 20 Hz the human ear begins to
perceive a series of individual clicks rather than a note. We call
the notes that the computer is able to play the ‘playable notes’.
Beats Frequency (Hz)
8 520.8
12 347.2
13 320.5
16 260.4
17 245.1
18 231.5
20 208.3
21 198.4
22 189.4
23 181.2
24 173.6
25 166.7
26 160.3
27 154.3
28 148.9
29 143.7
30 138.9
31 134.4
32 130.2
33 126.3
34 122.6
35 119.1
36 115.7
37 112.6
38 109.7
39 106.8
40 104.2
41 101.6
42 99.2
43 96.6