Here you can read some background articles related to Pandora's rise and fall:
"Pandora stock surges in IPO, then cools" CNN Money, June 15, 2011
"Pandora stock surges in IPO, then cools" CNN Money, June 15, 2011
"Sirius XM to Buy Pandora in Bet on Streaming Music" WSJ, Sept. 24, 2018
"Sirius XM Completes Acquisition of Pandora" Variety, February 1, 2019
"Sirius XM Finally Ends Pandora's Misery" The Motley Fool, February 20, 2019