How can I open the .idk file

Is there someone who can help me to open the .idk file extension. I have a HDD videoke player, I took some files on the player and try to open on computer. let say the file name is the song number

2678.mp3 - this is the song
2678.idk - this the lyrics

what software i need to open this at the same time to have have a audio and video.