In the latter half of the 1960s, thanks to the then-new technology of powerful amplifiers, rock and roll witnessed the emergence of the power rock trio. Its blues based "hard rock" music would pave the way for heavy metal, progressive (prog) rock, and other later strains of heavier rock. Sans keyboards, rhythm guitar or other instrumentation, and simply utilizing the basic guitar, bass, and drums (plus feedback), the power rock trio formula was born. Cream (comprised of Jack Bruce, Eric Clapton, & Ginger Baker) and The Jimi Hendrix Experience were among the early pioneers & ambassadors of this highly influential form of rock, and their combined influence was far reaching. Below are these two trios and several other late 60's into early 70's power rock trios spanning the formative half-decade from 1968 to 1973.

Included are video clips of Cream doing their classic "Sunshine Of Your Love" from 1968 and The Jimi Hendrix Experience (with Noel Redding on bass & Mitch Mitchell on drums) doing "VooDoo Child (Slight Return)" live on the Lulu Show on BBC TV in 1969. From 1968 is renowned San Francisco band Blue Cheer with their classic interpretation of Eddie Cochran's "Summertime Blues" from a decade earlier. The band, who typically were on the more psychedelic hard rock end but are more hard blues rock leaning here, featured vocalist and bassist Dickie Peterson, guitarist Leigh Stephens and drummer Paul Whaley. "Summertime Blues" was recorded for their 1968 debut album Vincebus Eruptum.

Written, recorded, and released back in 1935 by the great delta blues musician and songwriter Big Joe Williams, the song "Baby Please Don't Go" has been popular with countless artists in the seventy five years since, having been covered by dozens upon dozens of different musicians to the point that it ranks among the top ten most recorded blues songs in music's history. 

Perhaps the most famous or recognizable cover version of "Baby Please Don't Go" is the 1964 recording/release by Them -- the Belfast, Northern Ireland blues-rock ensemble featuring Van Morrison. Them's cover (with "Gloria" on the B side), which was a top ten single in the UK in 1965 and a US AOR radio staple in consequent years, injected a whole rock n roll energy into the classic blues song. 

So influential was Van & co's version that nearly all of the versions of the song recorded or just played after 1965 (including by fellow Irish blues-rockers Taste featuring Rory Gallagher) are rock inflected covers a la Them rather than the original blues version by Williams. Another Irish rocker to cover the song was guitarist / vocalist Eric Bell, who was an original member of Thin Lizzy.