Digital audio program material may be transferred from one system or location to another using a variety of methods. Recording media, such as disks and tapes, may be physically transported, but there are compatibility problems between systems; real-time interfaces may be used to replace analog interconnections for signal routing, and computer-style networks may be used for the transfer of audio in the form of data files. The relative merits of different approaches to program interchange with reference to operational requirements, and the various problems of data format and compatibility are examined.