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Revision 494, 0.8 kB
(checked in by shans, 1 year ago)
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Instruments created from simple wave functions (for now - from
parameterised sound functions soon!)
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type register = int;; |
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type tone = float;; |
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let c = 0;; |
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let d = 2;; |
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let e = 4;; |
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let f = 5;; |
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let g = 7;; |
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let a = 9;; |
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let b = 11;; |
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(* a is 440 Hz. Circle of 5ths gives 3/2 for each 5th above a. So: |
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* |
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* c 3^9/2^15 3^9/2^14 |
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* c# 3^4/2^7 3^4/2^6 |
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* d 3^11/2^18 3^11/2^17 |
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* d# 3^6/2^10 3^6/2^9 |
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* e 3/2^2 3/2^1 |
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* f 3^8/2^13 3^8/2^12 |
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* f# 3^3/2^5 3^3/2^4 |
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* g 3^10/2^16 |
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* g# 3^5/2^8 |
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* a 3^0/2^0 (3^12/2^19) |
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* a# 3^7/2^11 |
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* b 3^2/2^3 |
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* |
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* HOWEVER, we don't actually use pure tempering anymore, but approximations. |
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* In fact, we use equal exponential scaling, i.e. a*(s^12) = 2a, or |
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* s = 2^(1/12). We'll keep a at 440 Hz. So for a given v and reg we have |
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* 440*2^(1/12*(v-9+12*reg)) |
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*) |
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let note v reg = |
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let sfactor = float_of_int (v - 9 + 12 * reg) /. 12. in |
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440. *. (2. ** sfactor);; |
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