Edited sentence: Correction by CC; 5/07:  The MSEP parade at Disneyland never used radio control triggered syncronization of anything; it was strictly MANUAL.I personally ran the tape playback for the MSEP for the summer of 1974 (the last year it ran, giving way to America On Parade in 1975) and find it annoying when un-verified mis-information like the above and below is published without any qualification.Master Control took the seven channels of audio coming from the tape playback and manually cross-fed them to the different zones along the Parade route in sync with the Parade.They relayed information about the progress of the Parade to the command post located on a rooftop in the middle of Main Street and to a Master (audio) Control located in the top of Bank of America at the foot of Main Street.They were also simultaneously fed to seven modified Vega RF microphone transmitters with large rooftop antennas from the roof of the Castle and broadcast to Vega RF mic receivers located inside of the floats.Those seven audio channels originated from the "Alice Sound Room" located directly under the Peter Pan ride and next to "Alice's Adventure in Wonderland" ride, deep inside Sleeping Beauty's Castle and were played back from alternate tracks on a coaxial fourteen track Precision Instruments (PI) data logging tape recorder using one-inch tape running at 15 ips.What actually happened was that spotters along the Parade route all wore headsets sharing a common intercom channel.Where it used radios was to broadcast the various themes to the Parade floats so the themes would play in sync