Most ring tones are simple tonal melodies. For Nokia, the common format is [RTTTL], which has been upgraded to [RTX] for their SMS enabled Smart Messaging Nokring (??) phones. Other phones have their own [means and methods].
Some phones will accept MIDI files, and others will accept MP3s. Now imagine the possibilities. A room full of geeks, each pawing for their pants when someone's phone speaks out, "thwap Message for you, sir!"
There are three main types of ringtones:
Monophonic
These were the earliest of ringtones , they were short tunes played with basic tones. An many early phones you could also program your own tone in.
Polyphonic
Polyphonic was the next progression in rongtones. With Polyphonic up to 128 individual notes with different instruments could be used. At this point mobile phone creators started working to improve phone speakers
Music ring tones
This is the latest version of ringtones often called either music ring tones, voice tones, mastertones, realtones, singtones or true tones. This uses actual pieces of real music usually contained on AAC, MP3, WMA, WAV, QCP, or AMR format. Many cell phone manufacturers are including voice ringtones on most of their newly released phones, including Motorola, Nokia and Sony Ericsson.
Many companies have been set up to provide ringtones such as [jamster], many of them provide free ringtones to intice new members in such as [Ringtoneza]. Some of these services have been heavily critized in the press as they lock members into subscriptions that are hard to get out of.