Where chord symbols came from

The problem a chord symbol solves

Start with the practical situation, because everything else follows from it. A rhythm section has four players. The bass plays one note at a time, low. The piano plays four or five notes, in a register that stays out of the singer's way. The guitar plays whatever shape falls under the hand in that position. The vibraphone, if there is one, plays two notes and leaves the rest alone.

Write all of that out and you have four different parts, four sets of page turns, and four opportunities for a copying error. Change the key and you write it all again. Cut eight bars in rehearsal and you correct four pages.

Write Fmaj7 above the bar instead and you have one line of type that every one of those players can read, each taking from it the part of the information they need. The symbol names the harmony and refuses to name anything else: not the voicing, not the register, not the doubling, not the rhythm, not whether the chord is in root position. Those are the player's business.

That division of labour is the invention. The notation is just its packaging, and it has been repackaged several times.

Figured bass: the numbers came first

By about 1600 a new kind of part appears in printed Italian music: a single bass line, with numbers written under some of the notes. Lodovico Viadana's Cento concerti ecclesiastici of 1602 is the collection usually named as the landmark, though the practice was already in use by the composers around the first operas, Peri and Cavalieri among them, whose printed scores of 1600 carry a bass line meant to be filled in.

The part is called a basso continuo, and the numbers are called figures. They work like this. A bass note with nothing under it means: build an ordinary triad on top of me. A 6 means: there is a sixth above me, so play the sixth and the third and leave out the fifth. 6/4 means a sixth and a fourth above the bass. A 7 means a seventh above the bass. An accidental on its own alters the third above the bass, and a stroke through a figure raises it.

Notice what the figures do not tell you. Not how many voices to play. Not which octave. Not the rhythm, not the doubling, not whether to arpeggiate. A continuo player realises the part, and two good players realise the same page differently. If that sounds familiar, it should: it is exactly the contract a modern chord chart offers, three hundred and fifty years earlier.

But there is one deep difference, and it is the reason figured bass could not simply be carried forward. Figures count from the bass note. The bass note is the reference point, so the same chord gets a different figure every time it is inverted, and the figure tells you nothing about what the chord is.

Rameau, and the idea of a root

The thing that had to be invented was the root. In the Traité de l'harmonie of 1722, Jean-Philippe Rameau proposed that a chord has a fundamental bass, a basse fondamentale, which stays the same whichever of its notes happens to be at the bottom. C, E and G are the same chord whether the bass plays C or E or G.

That sounds obvious now. It was not obvious then, and every chord symbol you will ever read depends on it. Without a root there is nothing for the letter C to refer to.

Roman numerals came next. They are usually credited to Gottfried Weber, whose Versuch einer geordneten Theorie der Tonsetzkunst appeared between 1817 and 1821, building on work by his teacher Georg Joseph Vogler: upper case for major, lower case for minor, numbered by degree of the key. V7 in C major is a G7. In E flat major it is a B flat 7.

Roman numerals are wonderful for explaining what a piece of music is doing, and poor for playing from. To read them you have to hold the key in your head and do arithmetic, in real time, in the dark. If the tune modulates, the numerals shift under you. If you want to play the same tune in a different key you get the transposition for free, which is a real advantage, but you pay for it on every single chord.

One chord, three reference points

Here is the same sound written all three ways: the notes E, G and C, a C major triad with E at the bottom, in the key of C major.

Two things are worth noticing in that little table. The first is that the chord symbol is the only one of the three that names the chord itself, which is why it survived into practical use. The second is that even here the traditions disagree: many British-trained musicians would write that Roman numeral Ib rather than I⁶. Hold on to that, because disagreement is going to be the theme of the rest of this article.

Letters over the bar

The letter symbol did not arrive from music theory. It arrived from the fretted instrument department of the popular sheet music business.

Look at American sheet music from the 1920s and you find, printed above the vocal line, little grids of dots: ukulele chord diagrams, and later banjo and guitar ones, each with a letter name above it. The ukulele boom put those boxes on an enormous quantity of printed music. The letter was there to label the diagram. Somebody at some point realised the letter was doing the work on its own and the diagram was optional.

By the swing era the dance band library has a part type built entirely out of them: the rhythm part, which is a stave of oblique slash marks, one per beat, with chord symbols above. Piano, guitar and bass could all read from it. Nobody had to engrave four parts.

This is the point where the practice becomes recognisably what we still use, and also the point where documentation thins out. There is no committee minute, no first edition, no moment where the profession agreed on anything. It spread because it was cheap to print, quick to correct, and it worked.

Tune-Dex cards, fake books, and the Real Book

A working musician in 1950 needed a few hundred tunes at short notice, in a form they could read on a bandstand. The market answered in stages.

From 1942, George Goodwin sold Tune-Dex: index cards, one per song, each carrying the melody, the first line of the lyric, the chord symbols and the copyright details, mailed out by subscription to professionals. Legal, licensed, and designed as a filing system.

They were also, it turns out, the perfect raw material for a bootleg. Photograph a stack of Tune-Dex cards, bind the result, and you have a book of several hundred tunes that you can sell out of a car boot without paying anybody. That is the documented origin of a good deal of the early fake book trade. The name is honest about the intention: you are not reading an arrangement, you are faking one from a melody and some symbols.

The famous one came later. In the mid 1970s, students at Berklee College of Music in Boston compiled The Real Book: hundreds of jazz tunes, hand lettered in a distinctive calligraphy, unlicensed, sold under the counter for decades. Hal Leonard began publishing a legal, licensed edition in 2004, which also corrected a great many errors.

And errors there were. The old bootleg editions are notorious for wrong changes, wrong keys and wrong bars. That is worth knowing as a reader, because it settles a question beginners often have about charts: a chart is a report, not scripture. Somebody listened to a recording, or remembered a gig, and wrote down what they thought was happening. Two fake books will give you two different sets of changes for the same tune, and neither of them is the tune.

What the Real Book did do, without anyone deciding it, was set a house style. Its way of writing a minor chord with a dash and a major seventh with a triangle is, for a whole generation of players, simply what chord symbols look like.

Documented, and merely conventional

It is worth separating the two, because a beginner who thinks the whole thing is codified will be badly confused the first time they read someone else's chart.

Documented, and not really in dispute:

• Figured bass as a printed practice from around 1600, with the figures counted from the bass note.
• Rameau's fundamental bass, 1722, which is where the idea of a chord root comes from.
• Roman numerals in something like the modern form from Weber, 1817 to 1821.
• Letter symbols on printed popular music alongside fretted instrument diagrams in the 1920s.
• Tune-Dex from 1942, and its role in the bootleg fake book trade.
• The Real Book from the mid 1970s, and the licensed edition from 2004.

Convention, house style, or habit:

• Everything about how the symbol is spelled. Minor as m, min, mi or -. Major seventh as maj7, M7, ma7 or a triangle. Half diminished as m7♭5 or a slashed circle. All of these are current, all at once.
• Whether an inversion is worth writing down at all. Some copyists mark every one with a slash; most mark only the ones that matter to the bass player.
• The closest thing to a standard is a proposal, not an authority: Carl Brandt and Clinton Roemer's Standardized Chord Symbol Notation of 1976, written for the Los Angeles studio scene. It is a good book. It did not settle the question.
• Even the letters are local. German language practice calls B flat B and B natural H, which has caught out every visiting musician at least once.

And the letter system is not the only survivor. Nashville session work uses the Number System, credited to Neal Matthews Jr. of the Jordanaires in the late 1950s and extended by others since: scale degrees written as arabic numerals, so that when the singer wants the song a tone lower nobody rewrites anything. It exists because in that room instant transposition mattered more than absolute pitch names. Different problem, different notation.

The short version

1. c. 1600Figured bass in print. Numbers under a bass line, counted from the bass. The player realises the rest.
2. 1722Rameau's fundamental bass. A chord has a root that survives inversion.
3. 1817 to 1821Weber's Roman numerals. Function relative to a key. Excellent for analysis, awkward to play from.
4. 1920sLetter symbols on popular sheet music, next to ukulele and banjo diagrams.
5. 1930s to 1940sThe dance band rhythm part: slash marks and chord symbols, read by the whole section.
6. 1942Tune-Dex cards. Melody plus symbols, one tune per card, sold to professionals.
7. 1950s onwardFake books, mostly illegal, often photographed from Tune-Dex.
8. mid 1970sThe Real Book. Sets a repertoire and, by accident, a house style.
9. 1976Brandt and Roemer propose a standard. It is influential and not binding.
10. 2004A licensed Real Book, with the changes corrected.

What this means when you read a chart

Three practical consequences, all of them descended directly from that continuo part of 1602.

The symbol is deliberately incomplete. If a chart says Fmaj7 and you play F, A, C and E in that order in the middle of the keyboard, you have not read it wrong, and neither has the pianist who plays A, E and G. The notation declined to specify. That is a feature and it is the only reason one line of type can serve four instruments.

The spelling is somebody's house style. When you meet C-∆ on one chart and CmMaj7 on another, you have not found two chords. You have found two copyists.

The chart is a report. Somebody wrote down what they heard. If your ear disagrees with the page, your ear is a witness with as good a claim as the page. Check both.