He first saw the Grateful Dead play at one of Ken Kesey"s Acid Tests, and signed on as the band"s manager almost immediately. He started to book the band at small local venues like the Fillmore and the Avalon, places where other bands such as Jefferson Airplane, Big Brother and the Holding Company, and Quicksilver Messenger Service got their start. Within a few years, the Dead became more successful, and Scully helped negotiate their first record contract, with Warner Brothers
He also got them booked into larger concerts like the Monterey People’s Festival and Woodstock.
He remained one of the band"s key managers until 1984, then returned briefly in 1985. Scully was the co-author with David Dalton of the book Living with the Dead: Twenty Years on the Business with Garcia and the Grateful Dead.