Notes

Notes are individual pitches, the smallest indivisible elements of music. The term applies both to pitches as they sound on an actual musical instrument, as well as to the symbols used to represent them in musical notation.

Notes are combined in various ways to form chords and scales, which are the principles behind the fundaments of music: melody and harmony.

Note Names

Natural Notes

Western music uses 12 notes. Of these notes, seven have their own distinct names and are referred to as natural notes. The names we use for them are C, D, E, F, G, A and B. Here is a representation of them in the same order using traditional music notation:

The natural notes correspond to the white keys of a typical piano keyboard:

Most of the time, it is amply clear that when text or speech refers to note names like D, F etc., it refers to natural notes. In potentially ambiguous situations, it might help to spell out "D natural", "F natural", and so on. In written text, this can be abbreviated by using the natural sign from musical notation: D♮, F♮ etc.

Tone and Step

Musicians will often bandy about terms like "tone", "semitone", "step", and so on. This potentially confusing terminology is a way to measure distance between notes. A tone is also commonly referred to as a whole step. It can be divided into two semitones or half-steps, respectively. A semitone is the distance between, for example, the G in the above picture, and the black keys immediately surrounding it to the left and right. The measurement of a whole step, a tone, or sometimes even a whole tone, is two semitones, or the distance between F and G, or between G and A. There is also a whole step, or a tone, between E and the black key between F and G.

Enharmonic Notes

Speaking of the black keys: they are collectively referred to as enharmonic notes. This means that they sound the same but can be written in different ways. Enharmonic notes have no individual names of their own like C, D, G and so on, but are considered to be related to nearby natural notes. As you see, there is only one key between C and D. This note can either be considered as related to C or D, depending on the context:

To indicate that a natural note has been raised or lowered by a half-step, a sharp (♯) or flat (♭) sign—called an accidental—is added to the note:

For example, the note between C and D can be referred to either as C sharp (C♯, for short) or D flat (D♭).

Since any natural note can be assigned a sharp or flat sign, even some of the natural notes have enharmonic equivalents:

Double Sharps and Flats

Notes can also be raised or lowered by two half-steps. The double-sharp sign is similar to a lower-case X, the double-flat sign looks exactly the way the term sounds:

In the same fashion, a C can also be rewritten as a D double-flat (D𝄫), whereas a D might occur as a C double-sharp (C𝄪).

When double flats and sharps are used, most notes—natural or enharmonic—have two enharmonically equivalent notes:

Out of context, what to call a given note is mostly irrelevant, especially on instruments with equal temperament. However, in the context of a chord or scale , correct spelling is important. This is because our system of music notation is based on a system where scales have seven notes. The extra names are sometimes necessary for an uncluttered and logical note picture.

Register and Pitch Class

The Basics

A quick glance at a keyboard or a guitar neck will probably hint that there are considerably more notes than the 12 that we have been discussing thus far. A grand piano might very well have 88 keys, whereas a classical guitar has six strings and around 17 frets. Another reason that the keyboard lends itself well to a discussion of music theory is that there is a recurring pattern. There are regular spaces between the black keys: 2 + 3, 2 + 3, and so on.

These are in fact the very same notes, albeit in different registers. In music theory, there aren't 88 unique names for every note available on the piano, but the same 12 notes that reoccur in different registers, all the way from the very low to the very high.

The distance between one C and the next lower or higher C is called an octave, a Latin ordinal that literally means the eighth [note]. This since there are eight scale degrees between the same note in different registers. For that reason, register and octave are often used synonymously. Notes in different octaves are perceived as closely related. A common example is that when men and women sing together, the women will usually sing an octave higher.

If we approach this in a slightly more scientific way, another interesting fact emerges. The frequency relationship between two notes an octave apart is exactly 1:2.

Pitch Class

In music theory, the exact pitch is not always relevant. Therefore, theorists often use the term pitch class to refer to all Cs, F sharps, A flats etc. collectively as opposed to singling out an individual pitch. A music theory text might not always be consistently specific, but it is well worth knowing that when I (or someone else) refer to "a C", then it is probably any of them.

Pitch Notation

If you do wish to be very specific about exactly which note you are referring to, you need to use pitch notation. In the table below, the word octave very specifically means all 12 notes from C to B:

As an example, an average modern piano will have a range from A0 to C8. A six-string 24-fret electric guitar goes from E3 to E7. The tenor's "high C" is a C5 whereas that of the soprano is a C6.