Ever since the birth of the Atari ST, different chip music formats have had different ways to use them. If you are coding a chip music player for the Atari ST you would have to use dozens and dozens of special ways to replay music. But in the mid 90's, BDC of Aura crew became tired of this inelegant system and decided to fix the issue once and for all. He then created the 'SNDH' file format. SNDH is actually the original songfile and replaycode with a header bolted on top of the music and replayer. The header has a unified calling interface no matter what type of chip music is hidden beneath it, and it has extended datas about the music.