File generated by vielklang, a digital audio workstation (DAW) plug-in tool used for automatically creating musical harmonies; contains melody properties about an imported audio file (often a .WAV file); includes notes, keys, and tuning frequency information; used by vielklang when computing harmonies.

ZPA files are automatically generated by vielklang when an audio file is imported. This information acts as a cache so that vielklang does not have to recompute the data each time the audio file is used. The ZPA file is generated in the same directory as the source audio file and uses a compound file extension (e.g., ".wav.zpa"). ZPA files are also generated by NewTone, a pitch and time audio editing plug-in developed by zplane (the vielklang developers) for use with Image Line's FL Studio product. The plug-in uses vielklang's pitch editing technology. NOTE: ZPA files can be safely deleted since the software will just regenerate them the next time the source audio file is used.