Suspended six stories above the pulsing Pennsylvania Station, Madison Square Garden was surely one of the Dead’s power spots, with its spring-loaded floor and inner concourse circling the inside of the venue like an ever-throbbing life force. And this probably all went double during the Dead’s triumphant five-show September 1987 stay, their only time visiting with a Top 10 single on the Billboard chart. Though only newly-minted hitmakers, they’d long since translated the power of “Wharf Rat” to arenas, its mountain range of dynamics playing from a broken whisper to wild thunder, the “I’ll get up and fly away” transition sounding like a cliff-side cloudburst.