Short answers, pulled from the story.
"Misty Mountain Hop" references the "Legalise Pot Rally" held in Hyde Park, London, on the 7th of July, 1968, during which police made arrests for marijuana possession. The lyrics reflect Robert Plant's desire for a better society built on individual freedom and mutual support rather than the constraints the rally confronted.
"Misty Mountain Hop" appears on Led Zeppelin's untitled fourth album, released in 1971 by Atlantic Records. It was also released as the B-side to the single "Black Dog".
The most common interpretation links the title to the Misty Mountains in J. R. R. Tolkien's The Hobbit. The name evokes a journey toward a freer, wilder place, matching the song's lyrical theme of escaping social constraints.
"Misty Mountain Hop" was recorded at Headley Grange, a mansion in Hampshire, England, where Led Zeppelin sometimes lived and worked during recording sessions.
In 2019, Rolling Stone ranked "Misty Mountain Hop" number 10 on its list of the 40 greatest Led Zeppelin songs.
Yes. Plant performed "Misty Mountain Hop" at most of his solo concerts following Led Zeppelin's 1980 breakup. He also performed it with the surviving members of the band at the Ahmet Ertegun tribute concert on the 10th of December, 2007.