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.[60] Open tunings are common in blues and folk music,[59] and they are used in the playing of slide and lap-slide ("Hawaiian") guitars.[60][61] Ry Cooder uses open tunings when he plays slide guitar.[59]
When playing seventh chords, guitarists often play only subset of notes from the chord. The fifth is often omitted. When a guitar is accompanied by a bass, the guitarist may omit the bass note from a chord. As discussed earlier, the third of a triad is doubled to emphasize its major or minor quality; similarly, the third of a seventh is doubled to emphasize its major or minor quality. The most frequent seventh is the dominant seventh; the minor, half-diminished, and major sevenths are also popular.[79]
TrueFire's In The Jam delivers an unparalleled jamming experience for the practicing musician. The next best thing to being there live, In The Jam puts YOU in the jam with top artists. Each edition includes multi-track video jams organized into separate video and audio tracks for each of the instruments. You can mute, solo or adjust the volume of any track.

With so much information online about guitar theory, how do you know which sites to trust? Guitar teacher Zachary A. shares his top 10 favorite sites for learning about the guitar... Online resources for guitar theory are extremely helpful. You may want to explore the endless limits of the guitar, or maybe you're in need of a tiny refresher before your next lesson with a private teacher.  These 10 websites are all tremendously helpful tools for guitar players of all levels - beginner, interm

I have heard how giving you are in so many respects of music schooling and I must say that I am impressed. You remind me of the pure idealism that we had in starting Apple. If I were young, with time, I'd likely offer to join and help you in your endeavours. Keep making people happy, not just in their own learning, but in the example you set for them. 
A "guitar pick" or "plectrum" is a small piece of hard material generally held between the thumb and first finger of the picking hand and is used to "pick" the strings. Though most classical players pick with a combination of fingernails and fleshy fingertips, the pick is most often used for electric and steel-string acoustic guitars. Though today they are mainly plastic, variations do exist, such as bone, wood, steel or tortoise shell. Tortoise shell was the most commonly used material in the early days of pick-making, but as tortoises and turtles became endangered, the practice of using their shells for picks or anything else was banned. Tortoise-shell picks made before the ban are often coveted for a supposedly superior tone and ease of use, and their scarcity has made them valuable.

A capo (short for capotasto) is used to change the pitch of open strings.[28] Capos are clipped onto the fretboard with the aid of spring tension, or in some models, elastic tension. To raise the guitar's pitch by one semitone, the player would clip the capo onto the fretboard just below the first fret. Its use allows players to play in different keys without having to change the chord formations they use. For example, if a folk guitar player wanted to play a song in the key of B Major, they could put a capo on the second fret of the instrument, and then play the song as if it were in the key of A Major, but with the capo the instrument would make the sounds of B Major. This is because with the capo barring the entire second fret, open chords would all sound two semitones (aka one tone) higher in pitch. For example, if a guitarist played an open A Major chord (a very common open chord), it would sound like a B Major chord. All of the other open chords would be similarly modified in pitch. Because of the ease with which they allow guitar players to change keys, they are sometimes referred to with pejorative names, such as "cheaters" or the "hillbilly crutch". Despite this negative viewpoint, another benefit of the capo is that it enables guitarists to obtain the ringing, resonant sound of the common keys (C, G, A, etc.) in "harder" and less-commonly used keys. Classical performers are known to use them to enable modern instruments to match the pitch of historical instruments such as the Renaissance music lute.
Piezoelectric, or piezo, pickups represent another class of pickup. These employ piezoelectricity to generate the musical signal and are popular in hybrid electro-acoustic guitars. A crystal is located under each string, usually in the saddle. When the string vibrates, the shape of the crystal is distorted, and the stresses associated with this change produce tiny voltages across the crystal that can be amplified and manipulated.
The hardest thing about playing chords when you get started is changing between them. To effectively change between chords, you need to be economical with your movements. Spend a bit of time thinking about where your fingers need to be for each chord, and work out the most efficient way to move from one to the other. For example, from a C major, you can flatten your index finger so it covers the first string too and move your middle and ring fingers both down a string to switch to an F. Easy changes to start with are between C major and A minor and G major and E minor.
SFCM produces some of the most successful and influential classical guitarists in the world. Spearheaded by renowned faculty and complemented by visiting artists such as Marcin Dylla, the department honors the tradition of the classical guitar while cultivating innovation. The Harris Guitar Collection, housed at SFCM, gives students a chance to see—and play—some of the most extraordinary guitars of the last two centuries.