An mk1 file extension is related to some kind of Karaoke audio file format.
MK1 file extension - Karaoke audio data
What is mk1 file? How to open mk1 files?
File type specification:
The mk1 file extension is associated with some audio format used by some apps for Karaoke. The mk1 file stores audio data.
The MK1 file format seems to be obsolete and without support from developer, or producer.
This mk1 file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.