Polyphonic ringtones can create multiple tones and/or notes simultaneously. This produces a more natural and realistic sound for melodies compared to very old phones that could only produce one note at a time.
Unlike real-music ringers, polyphonic ringtones only simulate music using a pre-defined set of tones and instrument sounds. They cannot reproduce vocals or exact music.
Polyphonic ringers often come in file formats such as "MID" or MIDI.
Most polyphonic ringers can simulate the sound of various real instruments, instead of just tones. The more notes the synthesizer can play simultaneously, the nicer it sounds. Different phones support a different number of simultaneous instruments (chords) - anywhere from 4 to 72 or more.
Polyphonic ringtones should not be mistaken with the so called "True tones" (also known as "Real tones") which are simply audio recordings, typically in a common format such as MP3, AAC, or WMA.