Originally Posted by Wikipedia

Blues rock is a hybrid musical genre combining bluesy improvisations over the 12-bar blues and extended boogie jams with rock and roll styles. The core of the blues rock sound is created by the electric guitar, bass guitar and drum kit, with the electric guitar usually amplified through a tube guitar amplifier, giving it an overdriven character.

The style began to develop in the mid-1960s in England and the United States, as what Piero Scaruffi called, a "genre of rhythm'n'blues played by white European musicians". UK Bands (such as The Who, The Yardbirds, Led Zeppelin, The Animals, Fleetwood Mac, Cream and The Rolling Stones) experimented with music from the older American bluesmen, like Albert King, Howlin' Wolf, Robert Johnson, Jimmy Reed, Muddy Waters, and B.B. King. While the early blues rock bands "attempted to play long, involved improvisations which were commonplace on jazz records", by the 1970s, blues rock got heavier and more riff-based. By the "early '70s, the lines between blues rock and hard rock were barely visible", as bands began recording rock-style albums. In the 1980s and 1990s, blues rock acts returned to their bluesy roots, and some of these, such as the Fabulous Thunderbirds and Stevie Ray Vaughan, flirted with rock stardom."