standing at the podium with Stokowski". For the recording of The Sorcerer's Apprentice in January 1938, engineers at Disney collaborated with RCA Corporation for using multiple audio channels which allowed any desired dynamic balance to be achieved upon playback. The stage was altered acoustically with double plywood semi-circular partitions that separated the orchestra into five sections to increase reverberation. Though as the production of Fantasia developed, the setup used for The Sorcerer's Apprentice was abandoned for different multi-channel recording arrangements. On January 18, 1939, Stokowski signed an eighteen-month contract with Disney to conduct the remaining pieces with the Philadelphia Orchestra. Recording began that April and lasted for seven weeks at the Academy of Music, the orchestra's home which was chosen for its excellent acoustics. In the recording sessions, thirty-three microphones were placed around the orchestra that captured the music onto eight optical sound recording machines placed in the hall's basement. Each one represented an audio channel that focused on a different section of instruments: cellos and basses, violins, brass, violas, and woodwinds and tympani. The seventh channel was a combination of the first six while the eighth provided an overall sound of the orchestra at a distance. A ninth channel provided a click track function for the animators to time their drawings to the music. In the forty-two days of recording of film was used. Disney paid all the expenses which included the musician's wages, stage personnel, a music librarian, and the orchestra's manager that cost almost $18,000. When the finished recordings arrived at the studio, a meeting was held on July 14, 1939, to allow the artists working on each segment to listen to Stokowski's arrangements, and suggest alterations in the sound to work more effectively with their designs. Fantasound The Disney brothers contacted David Sarnoff of RCA regarding the manufacture of a new system that would "create the illusion that the actual symphony orchestra is playing in the theater." Sarnoff backed out at first for financial reasons, but agreed in July 1939 to make the equipment so long as the Disneys could hold down the estimated $200,000 in costs (equivalent to about $million in ). Though it was not exactly known how to achieve their goal, engineers at Disney and RCA investigated many ideas and tests made with various equipment setups. The collaboration led to the development of Fantasound, a pioneering stereophonic surround sound system which innovated some