Short answers, pulled from the story.
Hard rock began in the mid-1960s with the garage, psychedelic and blues rock movements. The genre emerged from the electric blues of the 1950s where guitarists like Pat Hare captured a grittier, nastier, and more ferocious electric guitar sound on records such as James Cotton's Cotton Crop Blues in 1954.
The architects of hard rock included Cream, Jimi Hendrix, Jeff Beck, Dave Davies, Keith Richards, and Pete Townshend. These pioneers pioneered the use of new guitar effects like phasing, feedback and distortion to create a new language of sound that prioritized volume, distortion, and emotional intensity over technical polish.
Led Zeppelin released their first two albums Led Zeppelin and Led Zeppelin II in 1969 while Deep Purple achieved their commercial breakthrough with their fourth album Deep Purple in Rock in 1970. Black Sabbath released Paranoid in 1970 and Deep Purple continued to define their unique brand of hard rock with their album Machine Head in 1972.
The opening years of the 1980s saw the deaths of Bon Scott the lead singer of AC/DC and John Bonham drummer with Led Zeppelin. AC/DC pressed on recording the album Back in Black in 1980 with their new lead singer Brian Johnson while Black Sabbath replaced original singer Ozzy Osbourne with Ronnie James Dio in 1979.
Bon Jovi achieved a commercial hit with It's My Life from their double platinum-certified album Crush in 2000 and AC/DC released the platinum-certified Stiff Upper Lip in 2000. Aerosmith released a platinum album Just Push Play in 2001 and Heart achieved their first hit album since the early 90s with Red Velvet Car in 2010.