Consider the piano keyboard. If we start on middle C and play every white note to the next C, we have played a C major scale. A scale is a set of ordered notes starting at one note and ending at the same note one octave higher. In this way, a scale is a very simple melody. In Western music, major scales refer to sequences of notes with the following pattern of semitones: 2, 2, 1, 2, 2, 2, 1. The numeral 2 means that we go up two semitones, whereas the numeral 1 means that we go up one semitone. In the C major scale, you play the scale by playing all of the white keys on the piano starting at one C and going to the next.
There are also other types of scales than the major scale. The minor scale has the following pattern of semitones: 2, 1, 2, 2, 2, 2, 1. For the C minor scale, you press the black key just below the E key in the scale, called E-flat (Eb). There is also the chromatic scale where you play all 12 keys in the piano from one octave to the next. In addition, there is the petnatonic scale played by playing only the black keys on the piano to get the sets of intervals. This scale has only 5 nots in it instead of 8 or 12.
In this illustration, you can play several scales over an octave on a piano.
To see the illustration in full screen, which is recommended, press the Full Screen button, which appears at the top of the page.
Below is a list of the ways that you can alter the illustration. The settings include the following:
Keyboard: click or touch a key to play the tone associated
with that key. The tone lasts as long as the click or touch. The graph will
plot that frequency until the next tone is played.
Play Major: Press to have a C major scale played up and then down.
Play Minor: Press to have a c minor scale played up and then down.
Play Chromatic: Press to have a chromatic scale played up and then down.
Play Pentatonic: Press to have a pentatonic scale played up and then down.
Pressing this button restores the settings to their default values.