Chords and Triads: In music, a CHORD is generally thought of as a simultaneous combination of notes.
"A chord in music is any set of notes that is heard as if sounding simultaneously. These need not actually be played together: arpeggios and broken chords may for many practical and theoretical purposes be understood as chords..." (From Wikipedia)
The first measure in the above example is a BROKEN CHORD or ARPEGGIO (Fmaj7). The second measure is the same chord, but in this case it is a BLOCK CHORD - the notes are played simultaneously.
A TRIAD is one of the most basic types of chords. A triad is a 3 note chord containing a root, third and a fifth. Here is an example:
Basic chords and triads can be expanded and presented in many different ways.
These pages have detailed information on many common variants, extensions and types of chords:
Chords and triads can be either MAJOR, MINOR, AUGMENTED or DIMINISHED. The quality is determined by the size of the 3rd and 5th.
If learning chords is either new, or unclear, go here for a review of intervals. Understanding intervals is vital to knowing and understanding chords.
Now we move on to MAJOR, MINOR, AUGMENTED and DIMINISHED chords.
A major triad has a major 3rd and a perfect 5th.
A minor triad has a minor 3rd and a perfect 5th.
A diminished triad has a minor 3rd and a diminished 5th.
An augmented triad has a major 3rd and an augmented 5th.