A chord consists of a collection of three or more notes that are played simultaneously. Two pieces of information specify a chord: the chord root and the chord type. The chord root specification is the name of one of the twelve pitches that can be found in one octave of the chromatic scale. The possible chord root names are: C, C# or Db, D, D# or Eb, E, F, F# or Gb, G, G# or Ab, A, A# or Bb, and B.
	If the root of a chord was C, this would mean that pitches of C in one or more of the octaves that a piano, guitar or orchestra is able to play should be played as part of the chord.
	The other pitches that must be played in a chord of a particular type are selected by a formula that is unique to that type of chord. The formula for the other chord pitches of a chord type specifies the harmonic intervals that must be formed when those pitches are sounded with the chord root.
	The formula for a major triad prescribes that such a three note chord should include the chord root, a pitch that is a major third interval above the root or which is any number of octaves above or below that pitch, and a pitch that is a perfect fifth above the root or which is any number of octaves above or below that pitch.
	If your major triad is built on a C root, this means that a C in any octave can be included in the chord and that at least one of those C must be sounded. All notes that are a major third above any of those C pitches are named E. Any E in any octave may be included in the chord and at least one of those E's must be included. All notes that are a perfect fifth above C are named G. Any G in any octave may be included in the chord and at least one of those G's must be included.
	As you can see, there is no particular chord that is THE C triad. When a C triad is specified in a score, any chord out of a class that includes thousands of particular chords can be selected to satisfy that specification. Speaking of C triads makes sense in music because each of the playable C triads shares a common feeling with all other possible C triads. If you play a melody above a chord that is specified by a particular chord root and type, you can change the octave of any pitch in the chord or add pitches that are one or more octaves above or below a pitch that is in the chord and not alter the emotional meaning of the melody notes.
	Let's listen to several different C triads. First listen to one where C, E, and G are all played in the 4th octave. Next, here's one where the C is played in the 3rd octave, the G is played in the 4th, and the E is played in the 5th. Here's one where an E is played in octave 3, and G and C are played in octave 4. Finally, here's a C chord that plays every C, E, and G in octaves 2, 3, 4 and 5.
	Let's repeat this exercise for the F7 chord. F7 chords are four note chords that include the root, the major third interval above the root, a perfect fifth above the root, and a minor seventh above the root. In this chord, any F in any octave may be played an at least one of those Fs must be played. Notes that are a major third above the F root would be named A, so any A pitch in any octave may be played in the chord and at least one of those As must me played. Notes that are a perfect fifth above the F root are named C, so any of the pitches named C in any octave can be played in the chord and at least one of those Cs must be played. Finally, notes that are a minor seventh above F are named Eb, so any of the pitches named Eb in any octave can be played in the chord and at least one of these Eb's must be played as part of the chord.
	The different ways that a chord can be rearranged are called voicings. Hear four different voicings of F7 chords in quick succession..