Music Theory Overview

Overview of Terms
The Notes

Octaves
Steps

Concert Tuning
Note Range Table

Overview of Terms

Rhythm & Percussion

All sound has a pitch. All sound is based upon frequency. Often many might consider percussive sounds to be without a pitch, but they all have a frequency that can be quantified. Most percussive sounds are in the very low frequency range and are difficult if not impossible for the human ear to define as a pitch, but they are there none the less. These details are not that important to most musicians, but can be important to sound engineers, mixers and music producers.

Rhythm can exist by itself without tonal accompaniment. The next subject, melody, also involves rhythm. A melody has a rhythm to it even without percussion. Although often used interchangeably, rhythm and percussion are not exactly the same thing. Something can have rhythm without being percussive. Percussion is rhythm created by something that makes a percussive sound, most often by striking.

Melody

Melody, also referred to as tune, voice or line, is a linear succession of musical tones that the listener perceives as a single entity. In its most literal sense, a melody is a combination of pitch and rhythm, while more figuratively, the term can include other musical elements such as tonal color. It is the foreground to the background accompaniment. A line or part need not be a foreground melody. It is what is most identifiable in a song. Melody can exist by itself or with accompaniment of percussion and harmony.

Harmony

Harmony is the combining of different tones together. Harmony is broadly understood to involve both a "vertical" dimension (frequency-space) and a "horizontal" dimension (time-space), and often overlaps with related musical concepts such as melody, timbre, and form.

Timbre

In music, timbre, pronounced phonetically like "tamber", also known as tone color or tone quality, is the perceived sound quality of a musical note, sound or tone. Timbre distinguishes different types of sound production, such as choir voices and musical instruments. It also enables listeners to distinguish different instruments in the same category (e.g., an oboe and a clarinet, both woodwind instruments).

In simple terms, timbre is what makes a particular musical instrument or human voice have a different sound from another, even when they play or sing the same note. For instance, it is the difference in sound between a guitar and a piano playing the same note at the same volume. Both instruments can sound equally tuned in relation to each other as they play the same note, and while playing at the same amplitude level each instrument will still sound distinctively with its own unique tone color. Experienced musicians are able to distinguish between different instruments of the same type based on their varied timbres, even if those instruments are playing notes at the same fundamental pitch and loudness.

The physical characteristics of sound that determine the perception of timbre include frequency spectrum and envelope. Singers and instrumental musicians can change the timbre of the music they are singing/playing by using different singing or playing techniques. For example, a violinist can use different bowing styles or play on different parts of the string to obtain different timbres (e.g., playing sul tasto produces a light, airy timbre, whereas playing sul ponticello produces a harsh, even and aggressive tone). On electric guitar and electric piano, performers can change the timbre using effects units and graphic equalizers.

Notes

Musical notes are based upon frequencies of sound waves. There are an infinite number frequencies, but the human ear can only detect frequencies roughly between 20Hz and 20kHz. The measurement of frequencies is defined in what are known as Hertz. The symbol for Hertz is Hz. Hertz represents a single frequency cycle per second.

Although there are infinite frequencies or notes, at some point in time, humans decided, in the western world at least, to limit the base frequencies to twelve tones of equal temperment.

12 Notes

There are 12 notes in a standard chromatic scale which represent distinct frequencies. These note groups repeat in what are known as octaves which range from very low frequencies to very high frequencies. Although the notes range from A to G, A is not the primary note that the keyboard is structured around, it is the note of C. Without getting too pedantic, this has to do with the history of music and what are known as modes.

The following illustration shows the twelve notes as they are laid out on a standard ebony and ivory piano keyboard.
The following represents an octave from C to C.

12 Notes
1	2	3	4	5	6	7	8	9	10	11	12	13
C	C^#/D^b	D	D^#/E^b	E	F	F^#/G^b	G	G^#/A^b	A	A^#/B^b	B	C

Octaves

In music, an octave, derived from the Latin term for eight, is a series of eight notes occupying the interval between (and including) two notes, one having twice or half the frequency of vibration of the other. The octave relationship is a natural phenomenon that has been referred to as the basic miracle of music, the use of which is common in most musical systems. The interval between the first and second harmonics of the harmonic series is an octave. In Western music notation, notes separated by an octave (or multiple octaves) have the same name and are of the same pitch class.

Octave Number

As stated above the twelve notes in an octave repeat from low to high. These repeating patterns are given numbers to distinguish one from another. The octave numbers are based on the C note. With some exception octaves range from zero to eight. The notes within these octaves are given numbers to designate which octave they belong to. Starting at C0 (C-Zero) the octave numbering goes as follows: (This refers to all accidentals as sharps) C0, C#0, D0, D#0, E0, F0, F#0, G0, G#0, A0, A#0, B0, C1, C#1,... and so on. You can see that the number increments at the note C.
The note referred to as Middle C is C4.

Steps

The tonal change between one note and the next is known as a half step. So for example the tonal change between C and C sharp is one half step. The tonal change between C and D is two half steps and is called a whole step. If we look at the steps on just the white keys of the keyboard, ascending from the note of C to the next C above, an uneven pattern of whole steps and half steps can be observed.

White Key Steps
C to D	D to E	E to F	F to G	G to A	A to B	B to C
Whole Step	Whole Step	Half Step	Whole Step	Whole Step	Whole Step	Half Step

It is important to understand what the terms half-step and whole-step mean.
These relationships will be important later when defining what scales are.

A440 Tuning (Concert Tuning)

The keys of a modern 88-key standard or 97-key extended piano in twelve-tone equal temperament, has the 49th key, the fifth A (called A4), tuned to 440 Hz and is referred to as A440 Tuning. This tuning is sometimes referred to as Concert Tuning. There are other equal temperment tunings that are sometimes used, but A440 is the most common. For example, the digital tuner on my phone can be set to tunings between A415 to A460.

Instrument Range

The piano keyboard is often referred to as the Master Instrument. The reason for this is that out of all instruments, the piano has the greatest range octave-wise.
A standard full size keyboard has 88 keys which span seven whole octaves plus a few notes. These typically start at A0 and end at C7. The Bösendorfer Imperial Grand Piano, one of the largest manufactured pianos, has 97 ((12 x 8) + 1 = 97) keys starting at C0 and ending at C8.

The following illustration is of an extended 97 key keyboard ranging from C0 to C8. C4 is what is known as Middle C. The A above Middle C is A4 and is the basis for 440 tuning (Concert Tuning).

Note Table

This table shows the Note Number, MIDI Note, Note Name and the Note Frequency when tunned to A440.
Middle C (C4) is highlighted as well as A4 is highlighted since it is the focal point for the keyboard's tuning.

MIDI Note:

MIDI is an acronym for Musical Instrument Digital Interface. MIDI is used in digital music to allow MIDI capable electronic instruments and equipment to comunicate with digital equipment such as computers or other MIDI capable instruments.
Note Name:

This indicates the name of the note and an integer indicating which octave the note is located within. As you'll see below this is important in the notation of music. Middle C is the focal point for much music notation and so it should be noted where it is located.
Note Frequency:

This is the note's frequency in Hertz with a keyboard tuned to A440. The frequency ranges are not that important to most musicians, but they can be important when composing music, mixing music, or when producing music.

Keyboard Notes Tuned to A440 Tuning
Note	MIDI Note	Note Name	Frequency
108	119	B8	7902.133
107	118	A^#8/B^b8	7458.620
106	117	A8	7040.000
105	116	G^#8/A^b8	6644.875
104	115	G8	6271.927
103	114	F^#8/G^b8	5919.911
102	113	F8	5587.652
101	112	E8	5274.041
100	111	D^#8/E^b8	4978.032
99	110	D8	4698.636
98	109	C^#8/D^b8	4434.922
97	108	C8	4186.009
96	107	B7	3951.066
95	106	A^#7/B^b7	3729.310
94	105	A7	3520.000
93	104	G^#7/A^b7	3322.438
92	103	G7	3135.963
91	102	F^#7/G^b7	2959.955
90	101	F7	2793.826
89	100	E7	2637.020
88	99	D^#7/E^b7	2489.016
87	98	D7	2349.318
86	97	C^#7/D^b7	2217.461
85	96	C7	2093.005
84	95	B6	1975.533
83	94	A^#6/B^b6	1864.655
82	93	A6	1760.000
81	92	G^#6/A^b6	1661.219
80	91	G6	1567.982
79	90	F^#6/G^b6	1479.978
78	89	F6	1396.913
77	88	E6	1318.510
76	87	D^#6/E^b6	1244.508
75	86	D6	1174.659
74	85	C^#6/D^b6	1108.731
73	84	C6	1046.502
72	83	B5	987.7666
71	82	A^#5/B^b5	932.3275
70	81	A5	880.0000
69	80	G^#5/A^b5	830.6094
68	79	G5	783.9909
67	78	F^#5/G^b5	739.9888
66	77	F5	698.4565
65	76	E5	659.255
64	75	D^#5/E^b5	622.2540
63	74	D5	587.3295
62	73	C^#5/D^b5	554.3653
61	72	C5	523.2511
60	71	B4	493.883
59	70	A^#4/B^b4	466.1638
58	69	A4	440.000
57	68	G^#4/A^b4	415.304
56	67	G4	391.995
55	66	F^#4/G^b4	369.9944
54	65	F4	349.2282
53	64	E4	329.627
52	63	D^#4/E^b4	311.127
51	62	D4	293.664
50	61	C^#4/D^b4	277.1826
49	60	C4	261.625
48	59	B3	246.941
47	58	A^#3/B^b3	233.0819
46	57	A3	220.0000
45	56	G^#3/A^b3	207.6523
44	55	G3	195.9977
43	54	F^#3/G^b3	184.9972
42	53	F3	174.6141
41	52	E3	164.8138
40	51	D^#3/E^b3	155.5635
39	50	D3	146.8324
38	49	C^#3/D^b3	138.5913
37	48	C3	130.8128
36	47	B2	123.4708
35	46	A^#2/B^b2	116.5409
34	45	A2	110.0000
33	44	G^#2/A^b2	103.8262
32	43	G2	97.99886
31	42	F^#2/G^b2	92.49861
30	41	F2	87.30706
29	40	E2	82.40689
28	39	D^#2/E^b2	77.78175
27	38	D2	73.41619
26	37	C^#2/D^b2	69.29566
25	36	C2	65.40639
24	35	B1	61.73541
23	34	A^#1/B^b1	58.27047
22	33	A1	55.00000
21	32	G^#1/A^b1	51.91309
20	31	G1	48.99943
19	30	F^#1/G^b1	46.24930
18	29	F1	43.65353
17	28	E1	41.20344
16	27	D^#1/E^b1	38.89087
15	26	D1	36.70810
14	25	C^#1/D^b1	34.64783
13	24	C1	32.70320
12	23	B0	30.86771
11	22	A^#0/B^b0	29.13524
10	21	A0	27.50000
9	20	G^#0/A^b0	25.95654
8	19	G0	24.49971
7	18	F^#0/G^b0	23.12465
6	17	F0	21.82676
5	16	E0	20.60172
4	15	D^#0/E^b0	19.44544
3	14	D0	18.35405
2	13	C^#0/D^b0	17.32391
1	12	C0	16.35160

108	B8	119	7902.133
107	A^#8/B^b8	118	7458.620
106	A8	117	7040.000
105	G^#8/A^b8	116	6644.875
104	G8	115	6271.927
103	F^#8/G^b8	114	5919.911
102	F8	113	5587.652
101	E8	112	5274.041
100	D^#8/E^b8	111	4978.032
99	D8	110	4698.636
98	C^#8/D^b8	109	4434.922
97	C8	108	4186.009
96	B7	107	3951.066
95	A^#7/B^b7	106	3729.310
94	A7	105	3520.000
93	G^#7/A^b7	104	3322.438
92	G7	103	3135.963
91	F^#7/G^b7	102	2959.955
90	F7	101	2793.826
89	E7	100	2637.020
88	D^#7/E^b7	99	2489.016
87	D7	98	2349.318
86	C^#7/D^b7	97	2217.461
85	C7	96	2093.005
84	B6	95	1975.533
83	A^#6/B^b6	94	1864.655
82	A6	93	1760.000
81	G^#6/A^b6	92	1661.219
80	G6	91	1567.982
79	F^#6/G^b6	90	1479.978
78	F6	89	1396.913
77	E6	88	1318.510
76	D^#6/E^b6	87	1244.508
75	D6	86	1174.659
74	C^#6/D^b6	85	1108.731
73	C6	84	1046.502
72	B5	83	987.7666
71	A^#5/B^b5	82	932.3275
70	A5	81	880.0000
69	G^#5/A^b5	80	830.6094
68	G5	79	783.9909
67	F^#5/G^b5	78	739.9888
66	F5	77	698.4565
65	E5	76	659.2550
64	D^#5/E^b5	75	622.2540
63	D5	74	587.3295
62	C^#5/D^b5	73	554.3653
61	C5	72	523.2511
60	B4	71	493.8830
59	A^#4/B^b4	70	466.1638
58	A4	69	440.000
57	G^#4/A^b4	68	415.3040
56	G4	67	391.9950
55	F^#4/G^b4	66	369.9944
54	F4	65	349.2282
53	E4	64	329.6270
52	D^#4/E^b4	63	311.1270
51	D4	62	293.6640
50	C^#4/D^b4	61	277.1826
49	C4	60	261.6250
48	B3	59	246.9410
47	A^#3/B^b3	58	233.0819
46	A3	57	220.0000
45	G^#3/A^b3	56	207.6523
44	G3	55	195.9977
43	F^#3/G^b3	54	184.9972
42	F3	53	174.6141
41	E3	52	164.8138
40	D^#3/E^b3	51	155.5635
39	D3	50	146.8324
38	C^#3/D^b3	49	138.5913
37	C3	48	130.8128
36	B2	47	123.47080
35	A^#2/B^b2	46	116.54090
34	A2	45	110.00000
33	G^#2/A^b2	44	103.82620
32	G2	43	97.99886
31	F^#2/G^b2	42	92.49861
30	F2	41	87.30706
29	E2	40	82.40689
28	D^#2/E^b2	39	77.78175
27	D2	38	73.41619
26	C^#2/D^b2	37	69.29566
25	C2	36	65.40639
24	B1	35	61.73541
23	A^#1/B^b1	34	58.27047
22	A1	33	55.00000
21	G^#1/A^b1	32	51.91309
20	G1	31	48.99943
19	F^#1/G^b1	30	46.24930
18	F1	29	43.65353
17	E1	28	41.20344
16	D^#1/E^b1	27	38.89087
15	D1	26	36.70810
14	C^#1/D^b1	25	34.64783
13	C1	24	32.70320
12	B0	23	30.86771
11	A^#0/B^b0	22	29.13524
10	A0	21	27.50000
9	G^#0/A^b0	20	25.95654
8	G0	19	24.49971
7	F^#0/G^b0	18	23.12465
6	F0	17	21.82676
5	E0	16	20.60172
4	D^#0/E^b0	15	19.44544
3	D0	14	18.35405
2	C^#0/D^b0	13	17.32391
1	C0	12	16.35160