KAR is the original format of audio files for creating karaoke, which are formed in a variety of software systems. It has the ability to save not only MIDI file data, but also lyrics. The KAR format is part of the .midi extension. In most cases, they are used as a source for adding special text to regular MIDI files, and they also differ from the Karaoke file. After all, there is no additional track with words that are synchronized with the main melody according to certain algorithms. As a rule, in order to realize the vocal part, you must apply the first track. For a stream of words, a second track is used. This file extension can be obtained using specialized software. But not only. It can also be created using MIDI keyboards that are connected to computer hardware. If there are appropriate plugins, then you can open the KAR file using the Media Player traditional for the Windows operating system. Anyone using the Mac OS platform can play KAR files in the Mireth Technology Music Man karaoke application. But the universal option for this pair of systems is PG Music Band-in-a-Box. This software is the most popular among analogues. Together with the .KAR extension, they sometimes provide reference data on where audio catalogs and item metadata associated with audio tracks are located. It is also possible that there is information about the artist and about the albums.
M4R is a highly specialized audio file format. This format (full name - iPhone Ringtone File) was developed by Apple's IT giant specifically for the iPhone. This format creates music ringtones for the iPhone. ITunes Ringtone is the main program for opening files with the extension .m4r, and their creation is mainly using Apple iTunes. Formally, M4R files can only be created from songs and other works purchased in the iTunes music store. The size of the created ringtone in the M4R format can be a maximum length of not more than 40 seconds.