The previously discussed I-IV-V chord progressions of major triads is a subsequence of the circle progression, which ascends by perfect fourths and descends by perfect fifths: Perfect fifths and perfect fourths are inverse intervals, because one reaches the same pitch class by either ascending by a perfect fourth (five semitones) or descending by a perfect fifth (seven semitones). For example, the jazz standard Autumn Leaves contains the iv7-VII7-VIM7-iiø7-i circle-of-fifths chord-progression; its sevenths occur in the tertian harmonization in sevenths of the minor scale. Other subsequences of the fifths-circle chord-progression are used in music. In particular, the ii-V-I progression is the most important chord progression in jazz music.
Guitar chords are dramatically simplified by the class of alternative tunings called regular tunings. In each regular tuning, the musical intervals are the same for each pair of consecutive strings. Regular tunings include major-thirds (M3), all-fourths, augmented-fourths, and all-fifths tunings. For each regular tuning, chord patterns may be diagonally shifted down the fretboard, a property that simplifies beginners' learning of chords and that simplifies advanced players' improvisation. The diagonal shifting of a C major chord in M3 tuning appears in a diagram.
An open tuning allows a chord to be played by strumming the strings when "open", or while fretting no strings. The base chord consists of at least three notes and may include all the strings or a subset. The tuning is named for the base chord when played open, typically a major triad, and each major-triad can be played by barring exactly one fret. Open tunings are common in blues and folk music, and they are used in the playing of slide and lap-slide ("Hawaiian") guitars. Ry Cooder uses open tunings when he plays slide guitar.
Conventionally, guitarists double notes in a chord to increase its volume, an important technique for players without amplification; doubling notes and changing the order of notes also changes the timbre of chords. It can make a possible a "chord" which is composed of the all same note on different strings. Many chords can be played with the same notes in more than one place on the fretboard.
Learning to play guitar is loads of fun, though playing chords may seem a little intimidating at first. Fear not, it is not much different than playing single notes: you're just playing them all at once! This article will walk you through the process of working out the fingering, and show you how to play some common chords. Pull out your axe, and rock on!
Guitars have been played since the Renaissance era, after descending from the ancient Greek instrument, the kithara. Or, at least, that's how the theory goes: the only real proof for this is the similarities between the Greek word and the Spanish word, quitarra. Early guitars often had four strings, evolving into the six-string version we know today in the late 1600s. Anton Stradivari, the famous violin-maker, also had a hand in making guitars. There's now only one Stradivarius guitar left in existence.