Tech house is a subgenre of house music that mixes elements of techno with house music. The term tech house developed as a short-hand record store name for a category of electronic dance music that combined musical aspects of techno, such as "ruggedbasslines" and "steely beats," with the harmonies and grooves of progressive house.The music originally had a clean and minimalproduction style that was associated with techno from Detroit and the UK.In the mid to late 1990s a scene developed in England around club nights such as Heart & Soul, and Wiggle, the latter run by Terry Francis and Nathan Cole.Other DJs and artists associated with the sound at that time included Charles Webster, Bushwacka!, Dave Angel, Herbert, Funk D'Void, Ian O'Brien, Derrick Carter, and Stacey Pullen.By late 2000 London nightclub The End, owned by one time Shamen rapper Richard West (Mr C) and Laylo Paskin, was considered the home of tech house in the UK.
As a mixing style, tech-house often brings together deep or minimal techno music, the soulful and jazzy end of house, some minimal techno and microhouse (especially with a soulful feel, such as Luomo’s music), and very often some dub elements. There is some overlap with progressive house, which too can contain deep, soulful, dub, and techno elements; this is especially true since the turn of the millennium, as progressive-house mixes have themselves often become deeper and sometimes more minimal. However, the typical progressive-house mix—which might integrate some funky house, trance, and even some hard techno at times—has more energy than tech-house, which tends to have a more “laid-back” feel. Tech-house fans tend to appreciate subtlety, as well as the “middle ground” that adds a “splash of color to steel techno beats” and eschews the “banging” of house music for intricate rhythms.
Also in contrast to most progressive house, which tends to have a progression over the course of the mix ending in an ecstatic release of energy at the end, tech-house often aims at achieving an even “groove.” Although there might be dips and peaks in the energy level — any interesting mix will have them, after all—they will be more on the restrained side. As such, tech-house is found to be as enjoyable a "headphone experience" as it is a dancefloor one.
As a musical (as opposed to a mixing) style, tech-house uses the same basic structure as house. However, elements of the house 'sound' such as realistic jazz sounds (in deep house) and booming kick drums are replaced with elements fromtechno such as shorter, deeper, darker and often distorted kicks, smaller, quicker hi-hats, noisier snares and more synthetic or acid sounding synth melodies from the TB-303, including raw electronic noises from distorted sawtooth and square wave oscillators.
Some producers also add soulful vocals and elements, and equally as much raw electronic sounds in their music. However, a rich techno-like kick and bassline seems to be a consistency amongst tech house music.
Electrotech arose in Western Europe in late 2000 as the result of mixing high-attack basses found in electroclash with general tech house structure. As such, compositions still featured simple, discernible lyrics and single-note basslines, however, the final sound had a somewhat rough, "fuzzy" attitude very commonly found in electroclash. Examples of electrotech include "All You Need" by Miss Kittin,"Keep Control" by Sono, "This World" by Slam and "I Want You" by Paris Avenue.
Deeptech is a derivative form of electrotech highly influenced by both progressive and dark house. No definite song illustrating deeptech exists, suggesting that the name might have been coined from various concepts that set a "deep" atmosphere, but were not popular enough to hit the mainstream.
...more info at http://en.wikipedia.org/wiki/Tech_house