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]

With that in mind, the inverse to this rule isn’t always true. During the Folk Boom of the 1950s and 60s, there were actually quite a few musicians who put nylon strings on steel string acoustics. This gave the guitar a very warm and relaxed tone, though should you choose to do this be aware that you’re going to get a lot less volume and a reduced response across the entire frequency range.

The intervals between the notes of a chromatic scale are listed in a table, in which only the emboldened intervals are discussed in this article's section on fundamental chords; those intervals and other seventh-intervals are discussed in the section on intermediate chords. The unison and octave intervals have perfect consonance. Octave intervals were popularized by the jazz playing of Wes Montgomery. The perfect-fifth interval is highly consonant, which means that the successive playing of the two notes from the perfect fifth sounds harmonious.
Russell, George (2001) [1953]. "Chapter 1 The Lydian scale: The seminal source of the principal of tonal gravity". George Russell's Lydian chromatic concept of tonal organization. Volume One: The art and science of tonal gravity (Fourth (Second printing, corrected, 2008) ed.). Brookline, Massachusetts: Concept Publishing Company. pp. 1–9. ISBN 0-9703739-0-2.
A slide, (neck of a bottle, knife blade or round metal or glass bar or cylinder) is used in blues and rock to create a glissando or "Hawaiian" effect. The slide is used to fret notes on the neck, instead of using the fretting hand's fingers. The characteristic use of the slide is to move up to the intended pitch by, as the name implies, sliding up the neck to the desired note. The necks of bottles were often used in blues and country music as improvised slides. Modern slides are constructed of glass, plastic, ceramic, chrome, brass or steel bars or cylinders, depending on the weight and tone desired (and the amount of money a guitarist can spend). An instrument that is played exclusively in this manner (using a metal bar) is called a steel guitar or pedal steel. Slide playing to this day is very popular in blues music and country music. Some slide players use a so-called Dobro guitar. Some performers who have become famous for playing slide are Robert Johnson, Elmore James, Ry Cooder, George Harrison, Bonnie Raitt, Derek Trucks, Warren Haynes, Duane Allman, Muddy Waters, Rory Gallagher, and George Thorogood.
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.