Aided by his friendship with music publisher Don Kirshner, a fellow alumnus of Upsala College, Klein worked as an accountant for the next several years, assisted by Henry Newfield, a CPA who was a friend from school and the Army, and Marty Weinberg, another CPA, under the name Allen Klein and Company. Klein's clients included Ersel Hickey, Dimitri Tiomkin, Steve Lawrence, Eydie Gormé, Sam Cooke, Buddy Knox, Jimmy Bowen, Lloyd Price, Neil Sedaka, Bobby Darin, Bobby Vinton, Scepter Records, and the estate of Mike Todd. A key early contact was attorney Marty Machat, who frequently performed legal work for Klein over the years.