Music Theory - Chords & Symbols

Triad     A triad is a group of three notes having a specific construction and relationship to one another. They are constructed on 3 consecutive lines or three consecutive spaces. Each member of the triad is separated by an interval of a third. The triad is composed of a Root, Third, and Fifth.

     There are four types of triads: major, minor, diminished and augmented.

Inversions of Triads
     All triads have three positions that they can be arranged in. The root, 1st inversion, and 2nd inversion.
Root Position Triad
     If the triad root is in the lowest voice then the triad is in Root Position.

1st Inversion Triad
     If the third of the triad is in the lowest voice the triad is the 1st inversion.

2nd Inversion Triad
     If the 5th of the triad is in the lowest voice, the triad is in the 2nd inversion.

Figured Bass
     Figured Bass was developed in the early Baroque period. It was a system of musical shorthand that made the writing of keyboard parts easier. It was customary for the composer to write out the bass line and to place Arabic numerals above or below the figured bass to indicate the harmonies. The keyboard part was called the continuo, which was improvised by the player.
     In figured bass the Arabic numerals represent the intervals that sound above a given bass part. Certain abbreviations have become well known.

Alterations
     Alterations from the given key signature are indicated by placing an accidental before the Arabic numeral.
     An accidental, such as a sharp, flat, or natural that appears by itself under a bass note indicates a triad in root position with the third interval above the bass note sharped, flatted or naturaled.
Any sharp, flat, or natural sign beside the Arabic number indicates that this interval above the bass note should be sharped, flatted, or naturaled depending on the symbol.
#6,   b6,   6,    #6
  4                   b4
Sometimes, composers used a slash through the Arabic number instead of a sharp. They both mean the same thing.
     Roman Numeral Analysis
     In the early 1800's, German composers started to use roman numerals to symbolize harmony. Each note in a scale can have a triad or chord built above it. Upper case (Major) and lower case (minor) Roman Numerals are used to indicate the type of chord. I, IV, V are major triads/chords, ii, iii, vi are minor triads/chords, and vii is diminished.