Rock music went to college in the Sixties. First it started pilfering from classical music and theater. Then someone had the psychedelic-induced idea to carry a single story over an entire album, just like in opera.
And thus the genie was unleashed: the concept record, simultaneously emblematic of rock at its most ambitious and its most pompous.
Some damn musicologist determined these to be the best examples of this form.
The Top 10 Concept Albums of All Time
Source: Guitar World