Music Theory is at the basis of music itself. To understand music, understand music theory first.








Intervals


An interval is the distance in pitch between any two notes. If the two notes are played together they form a "harmonic interval"; if one comes after the other, it is a "melodic interval".

Harmonic Interval	Melodic Interval

When we count intervals, both notes are included. For example, C to D, is a 2nd; C to E a 3rd; C to F a 4th and so on...
Intervals are described not only by their "number" but also by their "quality". The interval from a key-note to the 5th note above it (the dominant), for instance, is not just at "5th" but is named as a "perfect 5th".

In C major, the full names of the intervals between C and each of the other degrees are like this.

Major 2nd	Major 3rd	Perfect 4th	Perfect 5th	Major 6th	Major 7th	Perfect 8ve

The same intervals are of course produced by any other major key.

In a minor key, some intervals from the key-note are the same with those from the key-note of a major key with same tonice, namely the 2nd, 4th, 5th and 8ve. The 3rd, however, is different and needs a different name. It is called a "minor 3rd".

The above introduced intervals are those produced by the major and minor scales; as such they are called 'diatonic intervals". All others are "chromatic intervals".

If the upper note of a perfect or major interval is raised a semitone the interval becomes AUGMENTED; if the upper note of a minor interval is raised a semitone, it becomes major; if the upper note of a perfect or minor interval is lowered a semitone, it becomes DIMINISHED; if the upper note of a major interval is lowered a semitone, it becomes minor.





Clefs


There is a sign -- a clef -- placed at the beginning of every stave. There are several different clefs, but the most common one is the treble clef. It is also known as the "G clef", because the middle part of it is always looped around a line, and that line represents the G above middle C.

For the lower notes on the keyboard a different clef is used: the BASS CLEF or the "F Clef". Nowadays the clef is always placed on the 4th line.

This C CLEF was always centred on a line and indicated middle C. Originally it could be placed on any of the first four lines of the stave, but nowadays it is used only on the third and the fourth.





Key Signatures





Black notes on the keyboard take their names from the white ones. If they are to the right (i.e higher in pitch) they are said to be sharp; if they are to the left (i.e lower in pitch) they are said to be flat. Each black note, therefore, has two names, e.g C sharp or D flat, D sharp or E flat.


The musical sign for sharp is . Therefore C# means C sharp. Likewise, the sign for flat is , and Bb means B flat. On the stave these signs are placed BEFORE the notes () although in ordinary writing they come afterwards.


To return to the original white note after it has been made sharp of flat, a natrual sign is used. It is also placed the same way with sharps and flats in writing and on the stave.

enharmonics. e.g. F# is the enharmonic of Gb, and vice versa.

In G major, all the Fs will be F#s. It is not necessary to write in the sharps or flats every time they are needed. Instead they are shown at the beginning of the piece, immdiately after the clef and before the time signature, as below...



This direction about the sharps and flats to be used is called the Key Signature.

During the process of a piece of music other sharps or flats, not included in the key signature may sometimes be added to individual notes. Further, a sharp or a flat in the key signature may be cancelled by the use of a . Sharps, flats and naturals used in this way are called accidentals. Once an accidental has appeared in a bar, it remains in force until the end of the bar.

No Sharps or Flats	A minor	C major
1 sharp (F#)	E minor	G major
2 sharps (F#, C#)	B minor	D major
3 sharps (F#, C#, G#)	F# minor	A major
4 sharps (F#, C#, G#, D#)	C# minor	E major
5 sharps (F#, C#, G#, D#, A#)	G# minor	B major
6 sharps (F#, C#, G#, D#, A#, E#)	D# minor	F# major

Table Of Sharps In Major And Minor Scales

1 flat	(Bb)	D minor	F major
2 flats	(Bb, Eb)	G minor	Bb major
3 flats	(Bb, Eb, Ab)	C minor	Eb major
4 flats	(Bb, Eb, Ab, Db)	F minor	Ab major
5 flats	(Bb, Eb, Ab, Db, Gb)	Bb minor	Db major
6 flats	(Bb, Eb, Ab, Db, Gb, Cb)	Eb minor	Gb major

Table Of Flats In Major And Minor Scales