Learn a D major. This chord only requires the bottom four strings. Place your index finger on the 3rd string, 2nd fret. Your ring finger then goes on the 2nd string, 3rd fret, and your middle finger is the 1st string, second fret. You'll form a little triangle shape. Only strum these three strings and the 4th string -- the open D -- to sound out the chord.
Phosphor bronze strings have a warmer sound with a smooth (if somewhat understated) high end response. This makes them a great fit for genres that benefit from a mellower tone, like a lot of folk or finger-style work. These strings pair well with smaller bodied guitars, though many musicians who play more relaxed genres prefer these strings on larger bodied instruments as well.
As previously stated, a dominant seventh is a four-note chord combining a major chord and a minor seventh. For example, the C7 dominant seventh chord adds B♭ to the C-major chord (C,E,G). The naive chord (C,E,G,B♭) spans six frets from fret 3 to fret 8; such seventh chords "contain some pretty serious stretches in the left hand". An illustration shows a naive C7 chord, which would be extremely difficult to play, besides the open-position C7 chord that is conventional in standard tuning. The standard-tuning implementation of a C7 chord is a second-inversion C7 drop 2 chord, in which the second-highest note in a second inversion of the C7 chord is lowered by an octave. Drop-two chords are used for sevenths chords besides the major-minor seventh with dominant function, which are discussed in the section on intermediate chords, below. Drop-two chords are used particularly in jazz guitar. Drop-two second-inversions are examples of openly voiced chords, which are typical of standard tuning and other popular guitar-tunings.
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.