Showing posts with label Music Theory. Show all posts
Showing posts with label Music Theory. Show all posts

Friday, 26 July 2024

Guitar Humility

For reasons to do with me mentioning it, my tutor looked up Joni Mitchell’s Coyote on YT. Within a verse, he detected the down-tuned low-E string (to C), and had picked up the chords. I still have fumble-fingers making a C6/9 and would never have picked up the detuned E-string.

It’s one thing to know about (say) perfect pitch and ear training, but it’s another to see it action and understand the ocean-sized gap between an amateur and a proper musician. An untrained ear condemns us to a lifetime of sight-reading or tab.

Learning the major scales, modes, and even harmonic minors, octotonic and other weird stuff, is actually fairly simple as long as you can handle doing repetitive exercises. After that, finding the key a song is in is a matter of quietly trying this or that note (starting with F♯ then B♭ to figure out which side of the circle of fifths the song is in, and going round that way) until it sounds right. Then jamming along with the track using pentatonics or a major scale is a fairly easy and pleasing experience.

An experience that requires almost no knowledge of chords or harmony, no ability to read tab or stave, and no idea what clever chords are being used. It’s like being able to make an omelet and bake a simple cake and thinking you’re a cook. Or being able to speak tourist Spanish.

Problem is, it gives you an entirely false idea of just how much you know.

I came away from the third lesson, during which we went through the chords of Autumn Leaves as an example of moving in fifths, usefully angry with myself. I thought I had been fumbling on the fretboard like some beginner, and it was inexcusable that I heard the phrase “E♭major 7th” and didn’t automatically make the required shape. I know the major 7th shape on those strings, but I couldn’t bring the knowledge to use. Not good enough.

Playing guitar is like speaking English. The basics are easy, and one can communicate well-enough in it and still speak it badly (unlike, say, French or Dutch), but advanced use takes a very long time, and most people never get that far.

Part of the hump is learning the fretboard. There is no equivalent for pianists: F♯ below middle C is in one and only one place, but on the guitar, it can be played on the third string fourth fret, fifth string ninth fret, and sixth string fourteenth fret. And yes, each one sounds slightly different, because physics (overtones). Same with the violin family. Learning the fretboard is nowhere near as easy as you think it is, and nobody knows why.

Chords are even worse, and it doesn’t help that a chord of N notes can have at least N different names depending on which one is treated as the root. (Classical harmony gets over this by defining the root as the note that would the lowest if the notes were re-arranged in ascending thirds (or nearest approximation). It also does not help that - aside from the sus chords (2 and 4) - there are no even-numbered notes in chords. Chord intervals go 1-9-3-11-5-13-7 (unless the 9 is a sus 2 or the 11 is a sus 4). Also 7’s are all minor unless announced as major, and a diminished 7th is a 6th, but not in a 5/6 chord or a 6-chord (which is not to be confused with a VI chord, of course).

So your tutor can say “Esus ♭ 6” and leave you wondering WTF? Whereas they mean A-minor, which is a reflex to shape at the first fret, because it’s a cowboy chord. Not that tutors would do that.

Oddly, realising just how low on the learning pole I am, has introduced a lump of realism to whatever the heck I think my goals are.

Friday, 9 February 2024

Guitarists and Triadic Chords

Not only can we not play full-fledged triadic extended chords on the guitar, but we can’t always play the notes of a special-effects chord in triadic order. (We can always do that on a piano.) So guitarists jumble the notes around the fretboard until they find a combination they can play and call that the “D♭13”. If they can’t manage that, they drop one of the notes and try again. This is why guitar chord books will show two different chords in different positions under the same name with nary a word of explanation.

These variations are called “voicings” of the chord. Because that sounds like they meant it.

What does it mean to say you’re playing B♭minor 7♯9 on the guitar, if there are three ways of doing it and each of them has a different set of notes in a different sequence (from the sixth to the first string) and each voicing may be a third or more higher than the next?

It means two things: first that the triadic naming convention rapidly becomes unwieldy above sevenths; second, that you’re hip to the tricks of the trade you have the musical taste a) not to make a fuss about the ambiguities, and b) to know which of the “voicing” of an extended chord fits which situations.

It’s even worse than that. Many guitar chords are “voiced” across all six strings. So we can strum an accompaniment easily.

The strummer’s F-major chord in the first position is F-C-F-A-C-F. An F-major triad is F-A-C - in any key. The six-string chord has the 6-4 inversion (C-F-A), the fifth (F-A-C), and the sixth inversion (A-C-F). Two are major fifths (C-F-A, F-A-C) and a minor fifth (A-C-F). All in one chord. It’s triadic sludge. So are all the other cowboy chords (so-called because they can be strummed across all six strings in the first position).

Classical guitarists don’t strum, so this mess does not happen in classical music.

So does this mean (non-classical) guitarists are doing something wrong, or does it mean that conventional triadic harmony is not the best way of understanding what kind of harmonic contributions the guitar can make?

I would say the latter.

There’s a story about Joni Mitchell working with Tom Scott. She’s playing piano and Scott - a fearsome jazz session musician - is in the recording booth. Joni plays one of those “Joni Mitchell” chords, and Scott hits the mic and asks “Is that an A-flat 4th diminished 6th” (or some other such). Joni looks at him, then at her fingers on the keys, and then back again.

“Tom. Ignorance is bliss.”

I’d suggest that guitarist-harmony / chords is more bliss than book. The better songwriters find their “odd chords” by experiment as much as theory. The theorists then rave about so-and-so’s use of a minor ninth sus-2 (or whatever) as if so-and-so thought about it, when in fact, it’s a chord that results when playing something fairly ordinary and moving one finger forward a fret and another backward a fret. Experimenting. And do-able on stage.

Every guitarist has to learn the cowboy chords in all the shapes. And the sevenths and major sevenths, and the sus-2’s and sus-4’s. After that, it depends on what genre they are aiming for. As for learning lots of arpeggios? Only be-boppers do that, and be-bop dominates (non-classical) music teaching, because it has rules. (Of course, classical guitarists learn arpeggios, but that’s because a) Bach, and b) treating a sequence of notes across the strings as an arpeggio - and therefore a “chord shape” - is a way of learning the piece.)

Tuesday, 6 February 2024

Extended Chords

Next up are the chords made up of four notes. These are seventh chords, because four notes each a third apart are a seventh apart from top to bottom. (Weird interval arithmetic again.) In D-major these are:

D-F♯-A-C♯ I7 
E-G-B-D ii7 
F♯-A-C♯-E iiI7 
G-B-D-F♯ IV7 
A-C♯-E-G V7 
B-D-F♯-A vi7 
C♯-E-G-B vii7

Look at the cyclic permutations of (say) ii7 (E-G-B-D). These are: G-B-D-E; B-D-E-G; and D-E-G-B. These are a sixth wide, and have two notes next to each other, the D-E. The first is major, the second diminished (two semitones), and the third can be described as a sus2 (D-E-G) with an add 7 (B).

For a long time classical musicians stopped at seventh chords, with an occasional foray into a ninth as a stunt. Jazz musicians, however, started with sevenths and worked upwards, notionally to five note chords (ninths), six note chords (elevenths) and seven note chords (thirteenths). A jazz pianist or guitarist thinks nothing of playing D♭13, which is

Furthermore we can shift the fifths, sevenths, ninths and so on, up a sharp or down a flat, to get truly wonderful monstrosities such as D♭13: D♭(1)-F(3)-A♭(5)-C (7)-E&flat(9)-G♭(11)-B♭(13).

We can’t play the full-fledged Triadic D♭13 on the guitar, or with a string quartet, and it would need some skilful orchestration to be heard if played by an orchestra. Even if we could, we would only do so very rarely. It’s a mess. As are full-fledged elevenths.

Composers and songwriters know that chords extending above sevenths are a special effect. (Hindemith says as much in an aside in his book on Harmony.) They may want, say, the effect of the root and the eleventh (fourth an octave up), with the third to indicate that the chord is “really” a minor, and a flat (aka dominant) seventh, because that flavours the chord, but the fifth and the ninth don’t do anything musically useful, and are just clutter. So they write the root, third, seventh and eleventh, and everyone calls it an “eleventh chord”.

Suppose we want the special effect of a sharp nine against the eleventh? Write the root, sharp nine and eleventh. How about the third? Sharp nines are flat thirds an octave up, and that sounds messy, so let’s leave out the third. Dominant sevenths are a special effect of their own that will distract from the one we want, so let’s leave out the seventh. Let’s put in the fifth so that the chord doesn’t sound too thin. So that’s root, fifth, sharp nine and eleventh. Which is also called an eleventh chord, strictly an “eleven sharp nine” chord.

Nobody plays or writes full-fledged triadic extended chords. They play or write random carefully-chosen groupings of different notes spreading over two octaves. (Playing the same note an octave apart doesn’t “extend” the chord.) And no group of instrumentalists does this more than guitarists - and any other ensemble with less than five players.

Friday, 2 February 2024

Chords and Triadic Harmony

A tune is made up of a sequence of intervals.

Chords provide a background against which the melody is set.

Western chords start with Triadic harmony and get more complicated from there.

We start with… Triads. A Triad is a three-note chord. The simplest are fifths: the base note, the one a third in the scale above it, and the one a third above that. The triadic fifths of C-major are 

C-E-G      I
D-F-A      ii
E-G-B      iii
F-A-C      IV
G-B-D     V
A-C-E     vi
B-D-F     viio

Lower case indicates minor chords, upper case indicates major chords, the 'o' indicates a diminished chord. Minor chords have three semitones at the bottom (D-E-F is Tone-Semitone), and two Tones at the top (F-G-A is Tone-Tone). Major chords are the other way round. Diminished chords have two sets of three semitones (B-D-F is Semitone-Tone-Tone-Semitone). Augmented chords have two sets of four semitones (C-E-G♯ is Tone-Tone-Tone-Tone).

What happens if we play (say) E-G-C (in that order on the piano)? Now the interval at the bottom is minor, not major.

Flipping the notes of those triads around, we get the so-called Neapolitan Sixth chords

E-G-C I 6 (minor)
F-A-D II 6 (major)
G-B-E III 6 (major)
A-C-F IV 6 (minor / sort of diminished-ish)
B-D-G V 6 (minor)
C-E-A VI 6 (major)
D-F-B vii6 (minor)

Flip once more, we get the 6-4 triads

G-C-E I 46 (major)
A-D-F II 46 (minor)
B-E-G III 46 (minor)
C-F-A IV 46 (major)
D-G-B V 46 (major)
E-A-C VI 46 (minor)
F-B-D vii 46 (minor / sort of diminished-ish)

The 6-4 triads get their major or minor flavour from the top of the triad, rather than the bottom, as with the fifth and Neapolitan sixth triads.

All these chords have the property that adding another note a third above the top one just produces the bass note an octave higher. A-D-F goes to A-D-F-A. This is because in the weird arithmetic of notes, a sixth plus a third is an eighth. So these inversions are a Triadic dead-end - though we can add whatever note we want to any of them, and later on, we will.

The idea of the root of a triad was invented to explain why it is that C-E-G, E-G-C and G-C-E are all I chords in C even though they have different bass (bottom) notes. The root of a chord is the note that would be in the bass, if it was re-arranged as a series of ascending triads, filling in any missing notes and allowing for modifications.

Simple enough, surely?

Bassists play the root note, so the rest of us don’t have to.

Classical harmony theory loves these inverted triads, jazzers barely know they exist.

Tuesday, 30 January 2024

Roman Numeral Notation

Most music is written in one of the twelve major scales, and the Major scale has a pragmatically-central position in a (western) musician's technique.

Because all twelve major scales have the same intervals, anything we say about the musical properties of one scale will apply to any of the others. The Roman Numeral notation lets us do this: it abstracts out the tonic note, but fixes the Major scale.

I (tonic, first) the note that names the key
♯I / ♭II (sharp first, flat second) 
II (second)
 ♯I / ♭III (sharp second / flat third) 
III (third) 
♯III / ♭IV (sharp third / flat fourth) 
IV (fourth) 
V (fifth) 
♯V / ♭VI (sharp fifth / flat sixth) 
VI (sixth) 
♯VI / ♭VII (sharp sixth / flat seventh) 
VII (seventh) leading tone to the...
I an octave above the start

Counting the semitones from the tonic, these are the same names (without the adjectives like “perfect’) as the musical intervals defined in the previous post.

All the other (equal temperament) scales can be described in terms of this one:

Natural Minor / Aeolian Mode: I-II-♭III-IV-V-♭VI-♭VII
Major Blues: I-II-♭III-III-V-VI
Whole-Tone: I-II-III-♯IV-♯V♯VI

(The ability to recite any other scale or mode in terms of "sharp this, flat that" with utter fluency is an essential skill of any academic or jazz nerd. I'm not sure how much it helps, but it sounds impressive.)

Tuesday, 16 January 2024

Interval Names

(This is the first of two slightly dry posts on naming conventions.)

The intervals of European Equal Temperament scales are defined by counting the number of semitones between the notes and applying the following names (see here https://en.wikipedia.org/wiki/Interval_(music) for a longer discussion, including diminished and augmented intervals)

0 Unison P1
1 Minor second m2
2 Major Second M2
3 Minor third m3
4 Major third M3
5 Perfect fourth P4
6 Augmented fourth A4 / Diminished fifth D5
7 Perfect fifth P5
8 Minor sixth m6 / Augmented 5 A5
9 Major sixth M6
10 Minor seventh m7
11 Major seventh M7
12 Octave P8

The numbers 1,2,3... in the names are given by the number of lines and spaces ("staff positions") between the notes on the familiar five-bar stave. That method of counting notes will work for any scale with any number of notes in it.

C-F is... Tone(D)-Tone(E)-Semitone(F) = 5 semitones = Perfect fourth.

D-F is three semitones = Minor Third (D-E-F - D is on a line, E is in a space, and F is on a line, so an m3)

B-G♯ is Semitone(C)-Tone(D)-Tone(E)-Semitone(F)-Tone(G)-Semitone(G♯) = 9 semitones = Major sixth (G♯ is the sixth note in B-Major).

A♭ - E is Semitone(A)-Tone(B)-Semitone( C)-Tone(D)-Tone(E) = 8 semitones = Minor sixth (E♭ is the fifth note in A♭ and F is the sixth)

(You can use any method you like to count the semitones. This is my method at the moment.)

Since the number of semitones between any two notes is independent of the scale or key, interval names are independent of the underlying key or scale, since it depends only on the number of semitones. The same holds for staff positions, so the names of the intervals are also independent of the key or scale.

Friday, 12 January 2024

Scales

(We are now working in European Equal Temperament.)

A scale is any sequence of intervals (notice: not notes) that adds up to 12 semitones. Think of any bonkers combination, and someone somewhere will have a guitar tutorial explaining why it should be the very next thing you learn.

A key or mode is a scale plus a starting note (the "tonic") that then defines a sequence of notes. We say "the key of G-Major" scale or "the Major scale". (Musical speech is sloppy, so we also say "the Major key" or "the G-Major scale".) Two keys are equivalent if they have the same scale. “Scale” = intervals; key = notes.

There are a number of well-known seven-note scales:

Major / Ionian Mode: Tone-Tone-Semitone-Tone-Tone-Tone-Semitone
Natural Minor / Aeolian Mode: Tone-Semitone-Tone-Tone-Tone-Semitone-Tone
Harmonic Minor: Tone-Semitone-Tone-Tone-Tone-Tone-Semitone
Lydian Mode: Tone-Tone-Tone-Semitone-Tone-Tone-Semitone
Mixolydian Mode; Tone-Tone-Semitone-Tone-Tone-Semitone-Tone
Dorian Mode: Tone-Semitone-Tone-Tone-Tone-Semitone-Tone
Phrygian Mode: Semitone-Tone-Tone-Tone-Semitone-Tone-Tone

The Ionian, Aeolian, Lydian, Mixolydian, Dorian, Phrygian modes are often called Church Modes, as they were used in early choral singing.

There are two well-known five note (pentatonic) scales:

Major Pentatonic: Tone-Tone-Minor Third-Tone-Minor Third
Minor Pentatonic: Minor Third-Tone-Tone-Minor Third-Tone

Two well-known six note scales:

Major Blues: Tone-Tone-Semitone-Minor Third-Tone-Minor Third
Minor Blues: Minor Third-Tone-Tone-Semitone-Minor Third-Tone
(Minor Third = 3 semitones)

Exactly one scale of only tones: Whole-Tone: Tone-Tone-Tone-Tone-Tone-Tone (There are two keys: C and C♯. After that the notes repeat, so starting on D gives the same notes as starting on C.)

Exactly one scale of only semitones: Chromatic: Semitone (x12)

If you want to see something truly out of control, look at the eight-note diminished scale.

Tuesday, 9 January 2024

Intervals

This is the first of a series of posts about music notation and associated ideas. The world does not need this, but I do, to make my own sense of it. There is a lot of notation in music, and it's not all part of one coherent whole. It's a bunch of tools for specific tasks.

Let's start at the beginning.

A note is a name for a given frequency. The most well-known note is "middle C" (or C4) , followed by "A440", which is the frequency 440 Hz assigned to the A above middle C, A4.

The human auditory system regards two notes whose frequencies are in the ratio 2:1 as very harmonious. This is because musical instruments do not produce pure sine wave tones, but a sound that is a mixture of the fundamental frequency and many others, called “overtones”. Playing A440 will usually also generate an "overtone" of A880, and so it sounds pleasantly matching when played against A880 as a note. This is so much so that two notes related by double frequency are regarded as "the same but higher".

This splits the range of audible frequencies into ranges called octaves. Pick a starting position, say A4 = 440, and we have octaves as follows:

A7 = 3620 (almost the highest note on the piano)
A6 = 1760
A5 = 880
A4 = 440 (“tuning A”)
A3 = 220
A2 = 110
A1 = 55
A0 = 27.5 (lowest note on the piano)

(Why is it the lowest? There are pianos which go even lower, but below about 25Hz, the human ear stops hearing a continuous sound and starts to hear the individual beats. The highest note on the piano is 4120Hz and it's very difficult to produce an acoustic instrument that can produce that with significant volume.

The octaves are not the same size in terms of the range of frequencies, but the ratios of the frequencies are all the same. Each octave is double the previous one.

Each musical culture picks a different number of different frequencies within an octave to be its "notes". European music eventually settled on a series of frequencies, each one related to the previous one by the same ratio, the 12-th root of 2 (roughly 1.05946). This is called Equal Temperament, and it makes manufacturing and learning to play musical instruments way easier than the other European system did.

The "distance" between two notes is not measured in hertz (the ear doesn't work like that), but in powers of the 12-th root of 2 (roughly 1.05946). A power of the 12-th root of 2 is called a semitone. (Mathematicians can prove this is indeed a distance function as an exercise.)

Given a note X, the note one semitone up is X♯ and the note one semitone below is X♭. Replacing a note by the flat or the sharp is called flattening or sharpening the note. Under Equal Temperament, (X-1)♯ is the same note as X♭ - these are called enharmonic equivalents.

For more details, see the excellent and best-selling Your Brain on Music.