803.4 (C) Insufficiently Fixed Formats
Certain formats do not sufficiently fix a specific series of sounds. In such cases, the Office will not register a claim in sound recording. For example, standard midi files capture the underlying musical score, but they do not capture a specific series of sounds. While they contain instructions for producing sounds, any instrumentation may be applied, resulting in a file that contains different sounds each time it is played. For this reason, the Office does not consider standard midi files to be phonorecords and will not register a copyright claim in a sound recording contained in a standard midi file (although it may accept the claim as a musical work).