Research->Ringtone->File format of Ringtone Melody
This page provides information about various formats of ringtone file.
Each phone company uses different file format

Ringtone melody can be made by inputting numbers from keyboard of mobile phone. It also can be downloaded from some web site. However, music instruments and number of voice are different with companies and mobile phones. Therefore, method of inputting numbers and format of downloading are different with companies and mobile phones.

 SMAF and MFi
However, it is not true that each company and each mobile phone has different format. There is some standards. In general, there are two kinds of formats for mobile phones. One is SMAF which is used by J-Phone of Japan and some companies in Europe and US. File extension of SMAF is “MMF.” Another is MFi that is used by NTT of Japan and some companies in Europe and US. File extension of MMF is “MLD.”  
If you have information which company uses which format in your country, please send it to me.
(Ex. Nokia of England uses MMF file.)
 Similar structure to SMF
SMAF and MFi files have similar structure with SMF (Standard MIDI File). A file is divided into several brocks called chunk. Each chunk has header and event data. Since it must go through telephone network, its size must be small. Therefore format has some mechanisms to make file size small. For example, SMF and MFi has event that corresponds to NOTE-ON event, but there is no NOTE-OFF event. Instead of having NOTE-OFF event, NOTE-ON event includes gate time information.
 Specification of each format
Specification of SMAF can be downloaded from YAMAHA web site. Specification of MFi is not for public, but some Japanese site has information.
 Making Ringtone Melody File
There are some sequence soft for ringtone making. There also are some tools that take midi file and convert into ringtone file. Automated Composing System can convert MIDI files into SMAF, MFi, and other mobile phone files.