Yamaha SMAF

Yamaha Synthetic Music mobile Application Format, also known as SMAF, refers to the .mmf file format for SMAF songs and the synthesizer chips that support the format.

MMF File format
All MMF files have a header of  in hex or "MMMD " in ASCII.

SCAS
Synchronous Contents Authoring System, or SCAS, is a specification in SMAF used for animating sprites and text along with music in MMF files. It was originally intended to be used as an "animated" ringtone spec (PMD files can also do this, as seen on the Sanyo Katana) as well as MMS/email greetings.

Currently, no phones are confirmed to reproduce SCAS content in MMF files.