The Building Blocks of Music Part Two
Learning the basics of music theory need not be overwhelming. Just like mathematics, one concept builds on another. In the first part of this series, we reviewed basic notation and key signatures. This helped to explain what you are looking at when you see notes and accidentals on a music staff. We will now pick up where we left off.
Measures and Time Signature
When looking at a piece of music, you will notice vertical lines separating the staff. These separated parts of the staff are called bars or measures. Each measure has the same number of beats.
You will also usually see two numbers which are given at the beginning of a piece of music to indicate the number of beats in a measure http://neilhawes.com/sstheory/theory15.htm and the type of these beats. This is called a time signature. They are typically found right after the clef and the key signature, as shown here:
The top number represents the number of beats in the measure; the bottom number indicates the type of note that will measure each beat (in this case, a 4 representing a quarter note, with which four will create a full measure.) 4/4 is the most common time signature in popular music. 3/4 time is also quite common. Keep in mind that these do not represent mathematical fractions; this is actually a common misconception.
As it is known as “Common Time,” 4/4 time can also be represented by the letter C in place of the numerals, 2/2 as a letter C with a vertical line through it.
A new time signature can also appear at other places in the music where the number of beats per measure or the type of notes that represent the beat changes, in which case the new time signature applies from that point onwards. These must start at the beginning of a new measure.
The first beat in a measure is typically the strongest.
A double vertical line typically indicates the end of a piece of music.
In music, the word “scale” should be thought of much in the same way one would “scale a ladder.” One must go up the “rungs” of the scale (lines and spaces) with notes. A simple way to define a scale is any set of notes belonging to a single given key in which either all ascend or all descend in small steps. The key and the scale define each other; the notes will define the key, and thus the key signature (discussed in the previous article).
As there are two types of keys, so there are two types of scale: major and minor. There are two types of minor scales: melodic and harmonic. A major scale always has the intervals WWHWWWH where W=whole-step and H=Half-step. A melodic minor is WHWWWWH (up) and WWHWWHW (down). A harmonic minor is WHWWH3H (up and down), where 3=three half-steps.
More about Keys and Scales
Most pieces of music will start and end in the same key. In much the same way, all scales begin and end with the same note.
An exception to the major and minor scale rules is the chromatic scales, which use all the notes.