The heavy, psychedelic acid rock of Iron Butterfly may seem dated to some today, but the group was one of the first hard rock bands to receive extensive radio airplay, and their best-known song, the 17-minute epic "In-A-Gadda-Da-Vida," established that more extended compositions were viable entries in the radio marketplace, paving the way for progressive AOR…

Rock & roll had grown louder and wilder by leaps and bounds during the '60s, but when Blue Cheer emerged from San Francisco onto the national rock scene in 1968 with their debut album, Vincebus Eruptum, they crossed a line which most musicians and fans hadn't even thought to draw yet. Vincebus Eruptum sounds monolithically loud and primal today, but it must have seemed like some sort of frontal assault upon first release; Blue Cheer are often cited as the first genuine heavy metal band, but that in itself doesn't quite sum up the true impact of this music, which even at a low volume sounds crushingly forceful…

In the late '60s, when such things mattered, Ted Nugent was quickly gaining a reputation as a young-gun guitar hotshot, largely based on the back-to-back success of two singles issued by his group, the Amboy Dukes. The first, "Baby Please Don't Go," was a hopped-up rendition of the old blues standard, which Nugent and the band had learned off the version by Van Morrison's group, Them. The second was a group original, "Journey to the Center of the Mind," one of those tunes that shows up regularly on TV record ads for "Psychedelic Groovy '60s" collections. Nugent and the group continued to make great, musically interesting albums for the tiny Mainstream label, but had no more hits.