Electro house (also known as electronic house and dirty house) is a subgenre of house music that rose to become one of the foremost genres of electronic dance music in 2004-6. Stylistically, it takes the 4/4 beats and moderate tempo of 'normal' house and adds harmonically rich analogue basslines, abrasive high-pitched leads and the occasional old-school piano or string riff. There is much cross-pollination with minimal techno.
Roots of electro-house
The most obvious precursor to the modern electro-house scene is the electroclash movement of the early 2000s. Hotly hyped, it was largely a re-run of the classic early 80s Synth pop sound, but deliberately made cruder and more raw-sounding than even the primitive records on which it was based. It gathered popularity principally with fashionistas in Europe and North America, and without any real creative potential burned out quickly, since being generally considered a failure. However, the sound - as well as some of the artists and labels, notably Crosstown Rebels and City Rockers - have made a better fist of things by switching to electrohouse. Some artists - for instance, Felix da Housecat - associated with the movement had a noticeably housier sound even at the time and have since come to be seen as highly influential.
Previously and concurrent to electroclash, tech-house was developing. Traditionally, this had utilised more traditional Detroit influences, such as sweeping strings and 909 beats, but it developed a dirtier sound as the new millennium drew on, thanks largely to a trend of acid house revival (see for instance David Duriez and the Brique Rouge label).
In 2003 some tribal house DJs such as Steve Lawler, while previously associated with the darker-hued sounds of progressive house, began to use analogue basslines, starting the so-called 'dirty tribal' sound. Concurrently, the breaks scene did much the same with the popular tech-funk style. It was also at this time that the sound proper first began to emerge.
By 2005, the sound had become the dominant movement in house music, with DJs and producers from all over the spectrum finding common ground in its dancefloor sensibilities and sense of fun - John Digweed, Dave Seaman and others from the progressive house scene; Tiefschwarz and Ben Watt from deep house, Peace Division and Steve Lawler from tribal and so on.
some electro house tracks:
freeform five - no more conversations (mylo remix)
fedde le grande - put your hands up for detroit
cirez d - punch drunk