I stumbled upon this on YouTube.

“On July 3, 1969, two days before the Rolling Stones were to headline a free music festival in Hyde Park, their former guitarist Brian Jones drowned in his swimming pool. What was supposed to have been a party became, instead, a memorial.

About half a million people saw the Stones perform, including Mick Jagger’s girlfriend at the time, Marianne Faithfull. Before they played, Jagger read out Shelley’s poem Adonais, and 3,500 white butterflies were released. …”

— from The Times Magazine.

Here are the stanzas from the actual poem:

 39

  Peace, peace! he is not dead, he doth not sleep —

  He hath awakened from the dream of life —

  ‘Tis we, who lost in stormy visions, keep

  With phantoms an unprofitable strife,

  And in mad trance, strike with our spirit’s knife

  Invulnerable nothings. — We decay

  Like corpses in a charnel; fear and grief

  Convulse us and consume us day by day,

And cold hopes swarm like worms within our living clay.

52

  The One remains, the many change and pass;

  Heaven’s light forever shines, Earth’s shadows fly;

  Life, like a dome of many-coloured glass,

  Stains the white radiance of Eternity,

  Until Death tramples it to fragments. — Die,

  If thou wouldst be with that which thou dost seek!

  Follow where all is fled! ……..