Tones and Semitones
A semitone is the smallest distance between any two consecutive notes (higher or lower). The octave is divided into 12 semitones. Eg. C to C# is one semitone. Gb to G natural is one semitone. D to Eb is one semitone. E to F is one semitone (because there is no separate note for E#).
A tone is two semitones. Eg. C-D, F#-G#, E-F#.
Sharps and Flats
A sharp (#) raises a note by one semitone.
A flat (b) lowers a note by one semitone.
A double sharp (X) raises a note by two semitones (one tone).
A double flat (bb) lowers a note by two semitones (one tone).
A natural cancels out a sharp or flat.
Scales
The two most common scales now used in Western music are the Major and Minor scales. They are named after the note they start on. This note is referred to as the 'tonic'. Major and Minor scales have 7 different notes before ending up back on the tonic again (an octave higher).
Starting from the tonic and moving upwards, major scales all have the pattern of intervals:
Tone, Tone, Semitone, Tone, Tone, Tone, Semitone.
(Eg. C,D,E,F,G,A,B,C).
Natural minor scales all have the pattern:
Tone, Semitone, Tone, Tone, Semitone, Tone, Tone.
(Eg. A,B,C,D,E,F,G,A).
Note though, that the minor scale comes in different forms. In the harmonic minor (which is perhaps most common), the 7th of the scale is raised by one semitone. Thus the pattern becomes: Tone, Semitone, Tone, Tone, Semitone, Tone+Semitone, Semitone. (Eg. A,B,C,D,E,F,G#,A).
The melodic minor is more tricky. When going up, the 6th and 7th of the scale are both raised by one semitone. (Thus, the pattern becomes Tone, Semitone, Tone, Tone, Tone, Tone, Semitone). When going down however, the 6th and 7th are lowered back to normal, and you play it exactly the same as the natural minor.
The chief difference between major and minor is the third of the scale. In a major key the third is 4 semitones above the root, in a minor key the third is 3 semitones above the root.
The key of a piece indicates the scale around which the piece is written. (For example, a piece in the key of C major typically revolves around the C major scale).
Each note of the scale has a different technical name. In both major and minor scales:
1st of the scale = Tonic
2nd of the scale = Supertonic
3rd of the scale = Mediant
4th of the scale = Subdominant
5th of the scale = Dominant
6th of the scale = Submediant
7th of the scale = Leading Note
These names are also applied to the chords build up from the different notes of the scale, thus for example the 'Subdominant Triad' refers to the triad build up on the 4th degree of the scale.
(A triad is a 3 note chord made up of two superimposed 3rds (root, 3rd and 5th). Triads can be major, minor, diminished or augmented - more on that later.)
Written music
In all music, you will see something like this at the start:
Note, the five horizontal lines like this on which music is written is called the stave or the staff.
At the start of each stave you will see a clef. This indicates the pitch range of the stave (which notes go where).
Today, four different clefs are used: Treble, Alto, Tenor and Bass:
Note, the note shown is middle C in all cases.
The treble and bass clefs are most common, but violas, cellos, trombones and bassoons all make use of some of the others.
The Treble clef is also called a 'G clef', because the end of the squiggle always indicates where the note G is written.
The Bass clef is also called an 'F clef' because the line in-between the 2 dots indicates where the note F is written.
The Alto and Tenor clefs are also called 'C clefs' because the middle of the clef indicates where middle C is written.
Note that when a line is added below or above the stave (such as middle C in Treble and Bass clefs), this extra line is known as a ledger line (sometimes spelt without the d). In times gone by, different clefs were chosen to minimise the number of ledger lines needed (although, these days, ledger lines are quite common).
In Treble clef, from bottom to top, the notes on the lines are: E,G,B,D,F, and the notes in the spaces are F,A,C,E.
In Bass clef, from bottom to top, the notes on the lines are: G,B,D,F,A, and the notes in the spaces are A,C,E,G.
You can also sometimes get Octave Clefs. These are indicated by a small '8' above or below the clef. - This means the music should be played one octave higher (if above the clef), or one octave lower (if below the clef) than written. (Note though, these are rare and instruments such as Double Bass and Piccolo which naturally sound an octave lower or higher than written do NOT need the use of such clefs).
(Remember one octave is 8 notes (12 semitones); the difference between one note and the same note higher or lower on the keyboard).
Note, the clef at the far right of the above diagram is used for unpitched percussion. For this, pitch is not relevant so any of the other clefs would be inappropriate.
Key signatures
A key signature indicates the number of sharps OR flats in the prevailing key. Every key signature has one major key and one minor key associated with it. With minor keys, the key signature gives you the natural minor. Any raised 6ths or 7ths are NOT part of the key signature (and are instead included as accidentals).
A key signature is generally written on every line of the music. If the music does not have a key signature, it is either in C major, A minor, or it is Atonal (no prevailing key). Note, sharps are always added in the order F,C,G,D,A,E,B. And flats are always added in the order B,E,A,D,G,C,F.
I have already written about key signatures in this thread, so look there for further details.
An accidental is a sharp (#), flat (b) or natural sign written just before a note (indicating to raise or lower that note by a semitone). (They could also be a double sharp or double flat sign - see above). Accidentals are usually a temporary thing, and they are not part of the key signature (they may be foreign to the key). An accidental lasts for the entire duration of the bar in which it occurs. For example, once you have played one F# in a bar, every other F in that bar should also be sharpened unless counteracted with a natural sign. In the next bar, any previous accidentals are automatically cancelled out (unless a note with an accidental is tied over from the previous bar, in which case the accidental applies to the tied note also).
Time Signature
The time signature indicates the metre of the music. It usually consists of 2 numbers, the top number represents the number of beats in a bar, and the bottom number represents the 'type' of beat, expressed as a fraction of a semibreve (whole note).
Simple time signatures are where the basic beat is divisible by 2 . The basic beat is a crotchet (quarter note), which is divided into two quavers (eighth notes).
Compound time signatures are where the basic beat is divisible by 3. The basic beat is a dotted crotchet which is divided into three quavers.
1 semibreve = 2 minims = 4 crotchets = 8 quavers = 16 semiquavers etc. (regardless of time signature).
(See herodotus's thread for pictures of these notes, with both the American and British names).
Note though, sometimes you see the letter 'C' as a time signature. This means 'common time' and is essentially 4/4. The letter 'C' with a vertical line through it means 'cut time', 'cut common time', or 'alla breve', and is essentially 2/2.
Triplets are when you have 3 notes in the time of 2. Each note therefore makes up a third of the group (ie, a third of twice the note value).
Thus, crotchet triplets are 3 notes in the time of 2 crotchets (3 notes in the time of one minim - each note is 1/3 of a minim).
Quaver triplets are 3 notes in the time of 2 quavers (3 notes in the time of one crotchet - each note is 1/3 of a crotchet).
Triplet notes are written exactly as normal, except they have a little '3' above (or below) them. (Often the notes of the triplet are enclosed in a bracket or slur).
You can also get 'Quintuplets' which are 5 notes in the time of 4, 'Sextuplets' which are 6 notes in the time of 4, 'Septuplets' which are 7 notes in the time of 4 or 6, 'Nonuplets' which are 9 notes in the time of 8 etc.
Also, 'Duplets' (typically used in compound time) are 2 notes in the time of 3.
Note, any note(s) in the group may be replaced by a rest.
Intervals
An interval is the distance between any two notes (whether the notes are part of a melody or a chord).
Intervals are made up of both a number and a description.
The number is determined by the letters involved. Forget about sharps and flats for this bit, and count up how many notes there are between the two notes. - You count (include) both the starting note and the ending note. Eg. C-G involves 5 notes (C,D,E,F,G). C-G# also involves 5 notes, as does C#-G, and C#-G# (but note, C-Ab involves 6 notes not 5, even though G# and Ab are the same note).
This leaves you with a 1st (unison), 2nd, 3rd, 4th, 5th, 6th, 7th or 8th (octave). For any interval larger than one octave, just pretend it's in the same octave and add the word 'compound' in front of the interval.
Now for the description. This is either 'Diminished', 'Minor', 'Major', 'Perfect' or 'Augmented'.
The best way of working this out if as follows:
Consider this chart:
Consider the major scale of the lowest note involved (you will have to know its key signature).
For 1sts (unisons), 4ths, 5ths and 8ths (octaves): If the higher note belongs exactly to the lower note's major scale, the interval is said to be 'perfect'.
If the higher note is a semitone higher than the note of the lower note's major scale, the interval is said to be 'augmented' (the interval is greater).
If the higher note is a semitone lower than the note of the lower note's major scale, the interval is said to be 'diminished' (the interval is smaller).
For example, C-G is a 5th of some sort. G fits in with C major exactly, therefore C-G is a 'perfect 5th'.
With C-G#, the G# is NOT contained within C major, it is a semitone greater than a perfect 5th, therefore it is an 'augmented 5th'.
With C-Gb, the Gb is NOT contained within C major, it is a semitone lower than a perfect 5th, therefore it is a 'diminished 5th'.
For 2nds, 3rds, 6ths and 7ths: If the higher note belongs exactly to the lower note's major scale, the interval is said to be 'major'.
If the higher note is a semitone higher than the note of the lower note's major scale, the interval is said to be 'augmented' (the interval is greater).
If the higher note is a semitone lower than the note of the lower note's major scale, the interval is said to be 'minor' (the interval is smaller).
If the higher note is 2 semitones (a tone) lower than the note of the lower note's major scale, the interval is said to be 'diminished' (the interval is even smaller).
For example, C-B is a 7th. B is part of C major, therefore C-B is a 'major 7th'.
C-B#, the B# is a semitone greater than a major 7th, therefore it is an 'augmented 7th'.
C-Bb, the Bb is a semitone lower than a major 7th, therefore is it a 'minor 7th'.
C-Bbb, the Bbb (double flat) is 2 semitones lower than a major 7th, therefore it is a 'diminished 7th'.
Chords
Recall that a triad is a 3-note chord made up of a root, a 3rd above the root, and a 5th above the root.
The root is the 'tonic' of the chord; the basic note from which the other notes are derived. This is the note from which the triad is named. (Eg, in a C major triad, C is the root).
Major triads have a 'Major 3rd', and a 'Perfect 5th' above the root (see 'Intervals' above).
Minor triads have a 'Minor 3rd' and a 'Perfect 5th' above the root.
Diminished triads have a 'Minor 3rd' and a 'Diminished 5th' above the root.
Augmented triads have a 'Major 3rd' and an 'Augmented 5th' above the root.
A chord is a group of (typically 3 or more) notes sounded together. All triads are chords, but not all chords are triads.
In four-part harmony, you will obviously have to double up one note of the triad. The best note to double is the root (typically one octave higher), the next best is the 5th.
A chord in which the top three notes are as close together as possible is known as a chord in 'close position'. A chord in which the notes are more equally spread is known as a chord in 'open position'.
Chord inversions
The inversion of a chord is completely dependant on which note of the triad is the lowest note.
If the root is the lowest note, the chord is said to be in root position
If the 3rd is the lowest note, the chord is said to be in first inversion
If the 5th is the lowest note, the chord is said to be in second inversion.
Chord inversions are sometimes identified with figures representing the intervals within the chord.
Root position chords have the figure 5/3 (known as '5/3 chords') because there is a 3rd and 5th above the bass.
First inversion chords have the figure 6/3 ('6/3 chords') because there is a 3rd and a 6th above the bass.
Second inversion chords have the figure 6/4 ('6/4 chords') because there is a 4th and a 6th above the bass.
Note that the order and position of the other notes of the chord make no difference. E-G-C and E-C-G are both C major triads in first inversion. (It also doesn't matter how many notes are doubled, or how big a gap there is between notes).
Every note of every scale has a triad attached to it. These are labelled with Roman Numerals, starting with I for the Tonic Triad, and moving up to VII for the triad on the leading note (7th of the scale). I=1, II=2, III=3, IV=4, V=5, VI=6, VII=7.
In any major key, chords I, IV and V are major chords. (These are known as 'Primary Triads').
In any major key, chords II, III and VI are minor chords. (These are known as 'Secondary Triads').
In any major key, chord VII is diminished.
Chord inversions can also be indicated with a suffix to the Roman Numeral:
Root position chords add the letter 'a', 1st inversions add the letter 'b' and 2nd inversions add the letter 'c'.
Eg. IVb is chord IV in first inversion.
There. That's all for now, hopefully this will benefit someone. If anyone wants any clarifications, examples or has any questions, please let me know and I'll try to help.
