All traditional music instruments use this principle, with the instrument shapes and materials perfected through
the years to produce many overtones for each fundamental chord or key that is played by the user. Grand
pianos sound better than upright pianos since their larger shape enables them to produce more overtones,
especially at lower frequencies. Concert halls sound better than small rooms because they are designed for
best overtone performance and to take advantage of the fact that sound waves can reflect off walls to produce
different overtone relationships between both of your ears. The same thing applies to stereo sound. You may
have heard the term
acoustics, this is the science of designing rooms for best sound effects.
The most widely used musical scale (which measures pitch) will now be introduced; for more information please
refer to the references. This scale is called the
equal temperament scale, expressed in hertz. You might think
of this as a conversion table between the artistic and scientific worlds since it expresses pitch in terms of
frequency. Each overtone (overtone 0 being the fundamental) is divided into 12
semitones: C, C# (“C-flat”), D,
D#, E, F, F#, G, G#, A, A#, and B. The semitones increase by the ratio 12
√
2, or 1.05946.
Musical notes (tones)
are the measure of pitch and are expressed using both the semitone and the overtone, such as A3, G#4, D6,
A#1, and E2. Your AK-900 Electronic Keyboard plays notes from C3 to C6, in order across the keyboard.
(frequency in hertz and rounded off)
Up to now, the musical measures of pitch and loudness have been discussed. But many musical sounds have
the same pitch and loudness and yet sound very different. For example, the sound of a guitar compared to that
of a piano for the same musical note. The difference is a quality known as
timbre. Timbre describes how a sound
is perceived, its roughness. Scientifically it is due to differences in the levels of the various overtones, and so
cannot be expressed using a single number.
over-
C C# D D# E F F# G G# A A# B
tone
0 16.4 17.3 18.4 19.4 20.6 21.8 23.1 24.5 26.0 27.5 29.1 30.9
1 32.7 34.6 36.7 38.9 41.2 45.7 46.2 49.0 51.9 55.0 58.3 61.7
2 65.4 69.3 73.4 77.8 82.4 87.3 92.5 98.0 104 110 117 123
3 130 139 147 156 165 175 185 196 208 220 233 247
4 262 27 294 311 330 349 370 392 415 440 466 494
5 523 554 587 622 659 698 740 784 831 880 932 988
6 1047 1109 174 1245 1319 1397 1480 1568 1661 1760 1865 1976
7 2093 2217 2344 2489 2637 2794 2960 3136 3322 3520 3729 3951
8 4186 435 4698 4978 5274 5588 5920 6271 6645 7040 7459 7902
9
8372 8870 9397 9956 10548 11175 11840 12542 13290 14080 14917 15804
-5-
Summary of Contents for AK-900
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