NoteFreq

noteFreq is a public function that calculates the correct frequency for a given note. Notes are specified by MIDI note number, where 60 is middle C, and there are 12 notes per octave. Thus 61 is middle C#, 62 is D above middle C, and 72 (12 values above 60) is "high C" (one octave above middle C).

Usage Notes

Use the result of the `noteFreq` call as the frequency parameter to Sound.init (or assign it to Sound.freq. Assuming the waveform of the sound is a single cycle, the resulting sound will have the correct pitch for the note value passed to noteFreq.

It may also be used with digitized sounds, particularly when for digitized instruments. In this case, divide the noteFreq of the desired note by the noteFreq of the note for which the instrument was recorded (typically 60, middle C). Then use the resulting factor as the pitch parameter to Sound.play.

Example

This example plays a synthesized middle C for 1 second.

snd = new Sound
snd.init 1, noteFreq(60)
snd.play

The following example loads a digitized instrument (cello), plays it at its original pitch of middle C, and then plays it again as note 67 (middle G).

snd = file.loadSound("/sys/sounds/celloLongC4.wav")
snd.play  // plays as note 60 (C4)
snd.play 1, 0, noteFreq(67)/noteFreq(60)  // plays as note 67 (G4)

Value Table

The table below shows notes and frequency values for all 127 standard MIDI notes. However, the noteFreq function also accepts non-integer values, making off-pitch notes as desired.

Note Number	Musical Note	Frequency
0	C-1	8.1758
1	C#-1	8.6620
2	D-1	9.1770
3	D#-1	9.7227
4	E-1	10.301
5	F-1	10.914
6	F#-1	11.563
7	G-1	12.250
8	G#-1	12.979
9	A-1	13.750
10	A#-1	14.568
11	B-1	15.434
12	C0	16.352
13	C#0	17.324
14	D0	18.354
15	D#0	19.445
16	E0	20.602
17	F0	21.827
18	F#0	23.125
19	G0	24.500
20	G#0	25.957
21	A0	27.500
22	A#0	29.135
23	B0	30.868
24	C1	32.703
25	C#1	34.648
26	D1	36.708
27	D#1	38.891
28	E1	41.203
29	F1	43.654
30	F#1	46.249
31	G1	48.999
32	G#1	51.913
33	A1	55.000
34	A#1	58.270
35	B1	61.735
36	C2	65.406
37	C#2	69.296
38	D2	73.416
39	D#2	77.782
40	E2	82.407
41	F2	87.307
42	F#2	92.499
43	G2	97.999
44	G#2	103.83
45	A2	110.00
46	A#2	116.54
47	B2	123.47
48	C3	130.81
49	C#3	138.59
50	D3	146.83
51	D#3	155.56
52	E3	164.81
53	F3	174.61
54	F#3	185.00
55	G3	196.00
56	G#3	207.65
57	A3	220.00
58	A#3	233.08
59	B3	246.94
60	Middle C4	261.63
61	C#4	277.18
62	D4	293.66
63	D#4	311.13
64	E4	329.63
65	F4	349.23
66	F#4	369.99
67	G4	392.00
68	G#4	415.30
69	A4	440.00
70	A#4	466.16
71	B4	193.88
72	C5	523.25
73	C#5	554.37
74	D5	587.33
75	D#5	622.25
76	E5	659.26
77	F5	698.46
78	F#5	739.99
79	G5	783.99
80	G#5	830.61
81	A5	880.00
82	A#5	932.33
83	B5	987.77
84	C6	1046.5
85	C#6	1108.7
86	D6	1174.7
87	D#6	1244.5
88	E6	1318.5
89	F6	1396.6
90	F#6	1480.0
91	G6	1568.0
92	G#6	1661.2
93	A6	1760.0
94	A#6	1864.7
95	B6	1975.5
96	C7	2093.0
97	C#7	2217.5
98	D7	2349.3
99	D#7	2489.0
100	E7	2637.0
101	F7	2793.8
102	F#7	2960.0
103	G7	3136.0
104	G#7	3322.4
105	A7	3520.0
106	A#7	3729.3
107	B7	3951.1
108	C8	4186.0
109	C#8	4434.9
110	D8	4698.6
111	D#8	4978.0
112	E8	5274.0
113	F8	5587.7
114	F#8	5919.9
115	G8	6271.9
116	G#8	6644.9
117	A8	7040.0
118	A#8	7458.6
119	B8	7902.1
120	C9	8372.0
121	C#9	8869.8
122	D9	9697.3
123	D#9	9956.1
124	E9	10548
125	F9	11175
126	F#9	11840
127	G9	12544

Table is in Scientific Pitch Notation.