What is "triad"

Triad \Tri"ad\, n. [L. trias, -adis, Gr. ?, ?, fr.?, ?, three: cf. F. triade. See Three, and cf. Trias, Trio.]

1. A union of three; three objects treated as one; a ternary; a trinity; as, a triad of deities.

2. (Mus.)

   1. A chord of three notes.

   2. The common chord, consisting of a tone with its third and fifth, with or without the octave.

3. (Chem.) An element or radical whose valence is three.

   Triads of the Welsh bards, poetical histories, in which the facts recorded are grouped by threes, three things or circumstances of a kind being mentioned together.

   Hindu triad. See Trimurti.

1540s, "group or set of three," from Late Latin trias (genitive triadis), from Greek trias (genitive triados) "a triad, the number three," from treis "three" (see three). Musical sense of "chord of three notes" is from 1801. Related: Triadic.

n. 1 A grouping of three. 2 (context music English) A chord consisting of a root tone, the tone two degrees higher, and the tone four degrees higher in a given scale. 3 (context electronics English) on a CRT display, a group of three neighbouring phosphor dots, coloured green, red, and blue. 4 A branch of a Chinese underground criminal society, mostly based in Hong Kong.

1. n. the cardinal number that is the sum of one and one and one [syn: three, 3, III, trio, threesome, tierce, leash, troika, trine, trinity, ternary, ternion, triplet, tercet, terzetto, trey, deuce-ace]

2. a set of three similar things considered as a unit [syn: trio, triplet]

3. three people considered as a unit [syn: trio, threesome, trinity]

4. a 3-note major or minor chord; a note and its third and fifth tones [syn: common chord]

A triad, meaning a "group of three", may refer to:

In music, a triad is a set of three notes that can be stacked in thirds. The term "harmonic triad" was coined by Johannes Lippius in his "Synopsis musicae novae" (1612).

When stacked in thirds, the triad's members, from lowest pitched tone to highest, are called:

• the root
• the third – its interval above the root being a minor third (three semitones) or a major third (four semitones)
• the fifth – its interval above the third being a minor third or a major third, hence its interval above the root being a diminished fifth (six semitones), perfect fifth (seven semitones), or augmented fifth (eight semitones).

Such chords are referred to as triadic.

Some twentieth-century theorists, notably Howard Hanson and Carlton Gamer, expand the term to refer to any combination of three different pitches, regardless of the intervals amongst them. The word used by other theorists for this more general concept is " trichord". Others, notably Allen Forte, use the term to refer to combinations apparently stacked of other intervals, as in " quartal triad".

In the late Renaissance, western art music shifted from more "horizontal" contrapuntal approach toward chord-progressions requiring a more "vertical" approach, thus relying more heavily on the triad as the basic building block of functional harmony.

The root tone of a triad, together with the degree of the scale to which it corresponds, primarily determine a given triad's function. Secondarily, a triad's function is determined by its quality: major, minor, diminished or augmented. Three of these four kinds of triads are found in the major (or diatonic) scale.

In CRT or computer terminology, a triad is a group of three phosphor dots coloured red, green, and blue on the inside of the CRT display of a computer monitor or television set. By directing differing intensities of electron beams onto the three phosphor dots, the triad will display a colour by combining the red, green and blue elements. Each triad forms one pixel of the displayed image.

On LCDs, colours are similarly composed of these three colours.

The term Triad is used to designate certain historic groupings of seminal college fraternities in North America.

In sociology a triad is a group of three people. It is one of the simplest human groups that can be studied and is mostly looked at by microsociology. The study of triads, as well as dyads, was pioneered by German sociologist Georg Simmel at the end of the nineteenth century.

A triad is one of many branches of Chinese transnational organized crime organizations based in the PRC, Hong Kong, Macau, Taiwan and also in countries with significant Chinese populations, such as the United States, Canada, Vietnam, Korea, Japan, Singapore, Philippines, Indonesia, Malaysia, Thailand, the United Kingdom, Belgium, Netherlands, France, Spain, South Africa, Australia and New Zealand.

In the histology of skeletal muscle, a triad is the structure formed by a T tubule with a sarcoplasmic reticulum (SR) known as the terminal cisterna on either side. Each skeletal muscle fiber has many thousands of triads, visible in muscle fibers that have been sectioned longitudinally. (This property holds because T tubules run perpendicular to the longitudinal axis of the muscle fiber.) In mammals, triads are typically located at the A-I junction; that is, the junction between the A and I bands of the sarcomere, which is the smallest unit of a muscle fiber.

Triads form the anatomical basis of excitation-contraction coupling, whereby a stimulus excites the muscle and causes it to contract. A stimulus, in the form of positively charged current, is transmitted from the neuromuscular junction down the length of the T tubules, activating dihydropyridine receptors (DHPRs). Their activation causes 1) a negligible influx of calcium and 2) a mechanical interaction with calcium-conducting ryanodine receptors (RyRs) on the adjacent SR membrane. Activation of RyRs causes the release of calcium from the SR, which subsequently initiates a cascade of events leading to muscle contraction. These muscle contractions are caused by calcium's bonding to troponin and unmasking the binding sites covered by the troponin-tropomyosin complex on the actin myofilament and allowing the myosin cross-bridges to connect with the actin.

The Triad is an approach by the United States Environmental Protection Agency to decision-making for hazardous-waste site cleanup. During the late 1990s, technology advocates from the environmental sector in the United States developed the approach by combining innovations in management and technology with ideas from hazardous-waste site cleanup experience.

Their goal was to form a framework for real-time environmental sensors and tools, to improve decision-making at contaminated sites. This resulted in a more formalized set of ideas in 2001 that soon became known as the Triad approach. The ideas spawned a Community of Practice by 2005.

The Triad Community of Practice includes representatives of federal, state, and private sector organizations in the U.S. and abroad. By 2008, a European CoP had been formed In 2008, a technical conference led largely by the CoP and covering the Triad Approach was held at the University of Massachusetts in Amherst, "Triad Investigations: New Approaches and Innovative Strategies."

The term Triad represents three elements: systematic project planning (SPP), dynamic work strategies, and innovative rapid sampling and analytical technologies. While elements of the Triad have long been used for site cleanup, Triad packages these best management practices together with the guiding principles:

1. Use a planning process, which includes participation of all stakeholders (including a multidisciplinary project team, federal and state regulators, legal counsel, community members, and other environmental professionals), to determine the types of data required and to evaluate whether the site could benefit from real-time measurement technologies.
2. Discussion of uncertainty management, data representativeness, and site closure strategies.
3. Use of a site model that recognizes site characterization is an element used at all stages of remediation.
4. Use of sampling, measurement, and data management technologies to support uncertainty management strategies.
5. Project teams that have communication, trust, discussion of individual interests and goals, and expertise in the appropriate fields.

Triad is an open-marketplace idea that is not owned by one entity. There is considerable U.S. Multiagency support for Triad. Beginning in 2006, The U.S. Environmental Protection Agency Office of Superfund Remediation and Technology Innovation expressed support of Triad by requesting the cooperation of its regional managers to expand the use of Triad at Superfund sites, where appropriate.

Triad was a Swedish pop trio consisting of the trio Janne Bark, Lasse Lindbom and Niklas Strömstedt. Triad is most famous for their 1987-1988 Swedish number-one single hit Tänd ett ljus ("Light a Candle"), one of the Swedish classics song for the Advent season, just prior to Christmas. The outro includes Christmas and New Year's greetings in different languages. The single topped the Swedish singles chart on 6 January 1988. The song charted at Svensktoppen for eight weeks during the period 20 December 198714 February 1988. It has been subject to many cover versions.

The band was formed by three music friends. Janne Bark played the guitar, Lasse Lindbom of the Lasse Lindbom Band, was bassist and producer, and guitarist Janne Bark and Niklas Strömstedt played the piano. All three were vocalists.

The only album of the band, the self-titled Triad didn't prove successful reaching only #44 in the Swedish Albums Chart in May 1988. Soon after Triad disbanded. Niklas Strömstedt went on to have a successful solo music career for many years.

Triad reunited for a gig for Sveriges Television (SVT)'s sing-along show Allsång på Skansen on 16 August 2011.

Triad'' (German:Dreiklang'') is a 1938 German drama film directed by Hans Hinrich and starring Lil Dagover, Paul Hartmann and Rolf Mobius.

Triad is an outdoor sculpture by German American artist Evelyn Franz, located in Laurelhurst Park in southeast Portland, Oregon.

"Triad" is a song written by David Crosby in 1967 about a ménage à trois, a subject perfectly in keeping with the " free love" hippie philosophies of the day. The song was written while Crosby was a member of the rock band The Byrds, who were at that time recording their fifth studio album, The Notorious Byrd Brothers. Although the band did record "Triad" and perform it live during a September 1967 engagement at the Whisky a Go Go, it was not included on The Notorious Byrd Brothers album. According to Crosby, fellow bandmates Roger McGuinn and Chris Hillman felt that its subject-matter was too controversial, with McGuinn allegedly deriding the song as a "freak-out orgy tune." However, this has since been denied by Hillman who has stated "I don't think it was a moral decision. The song just didn't work that well. David was drifting and bored and wanted to do something else, and that song just added fuel to the fire."

There had been growing animosity between Crosby and the rest of the band throughout 1967. Tensions had arisen from several factors, including Crosby's displeasure over the band's wish to record the Goffin– King composition " Goin' Back", his fraternization with fellow L.A. musicians, and his controversial remarks to the audience during The Byrds' performance at the Monterey Pop Festival. These factors, along with the discord over "Triad", contributed to McGuinn and Hillman's decision to fire Crosby in October 1967. Crosby gave the song to Jefferson Airplane, who recorded it on their 1968 album, Crown of Creation. A live recording of "Triad" was later included on Crosby, Stills, Nash & Young's 1971 album, 4 Way Street.

The song's lyrics were largely inspired by the sexual freedom that Crosby enjoyed at his home in Beverly Glen in Los Angeles. However, the song also features allusions to author Robert A. Heinlein's science fiction novel Stranger in a Strange Land, with references to "sister lovers" and "water brothers". "Triad", as recorded by The Byrds, remained unreleased for twenty years until the 1987 archival album, Never Before. It also appears on the The Byrds box set from 1990, as a bonus track on the 1997 Columbia/Legacy reissue of The Notorious Byrd Brothers, and on the 2006 There Is a Season box set.

Actress and singer Sally Kellerman recorded the song in 1973 and released it as a single. The Icicle Works recorded "Triad" as a medley with another Byrds' song, " Chestnut Mare", on the 1989 Byrds' tribute album Time Between – A Tribute to The Byrds. The song was also covered by Danish singer-songwriter Tina Dico in 2008.