Iron Butterfly is an American rock band formed in San Diego, California, in 1966, primarily known for pioneering the psychedelic rock and heavy metal genres. Their most notable work is the 1968 album "In-A-Gadda-Da-Vida," which features the iconic title track—a 17-minute song characterized by its heavy use of organ, distorted guitar riffs, and extended instrumental solos. This track became a defining anthem of the late 1960s counterculture and is often credited with helping to popularize the concept of the "album-oriented rock" format. Iron Butterfly's sound is marked by a blend of hard rock, progressive rock, and psychedelia, influencing many future artists in these genres. Their fusion of heavy instrumentation and experimental sounds helped pave the way for heavy metal bands that followed. The band faced lineup changes over the years, but they regained some prominence in the 1970s and beyond through tours and reunions. Despite their relatively brief period of commercial success, Iron Butterfly's legacy endures, and their music remains a touchstone in the history of rock, illustrating the evolution of music during a transformative era.