| ikx | iKlax Creator Audio |
| ilb | Scream Tracker 2 Instrument Library |
| ilbc | Internet Low Bit Rate Codec Audio |
| ima4 | IMA 4-bit ADPCM Compressed Audio |
| ime | iMelody Ringtone |
| imelody | iMelody Ringtone |
| ims | IMPlay Song |
| imy | iMelody Ringtone |
| ins | EPSDisk Instrument File |
| ins | HSC-Tracker Instrument |
| ins | Cakewalk Sonar Instrument Definition |
| ircam | IRCAM SoundFile |
| isma | IIS Smooth Streaming Audio |
| it | Impulse Tracker Music Module |
| iti | Impulse Tracker Instrument |
| its | Impulse Tracker Music Sample |
| itz | Impulse Tracker Music Module |
| j6s | Ricoh Digital Camera Sound |
| jat | JUCE Audio Thumbnail Data |
| jcb | JCB-JCBrooke Music Module |
| jge | Roland Juno-G JGE Data |
| jgl | Roland Juno-G JGL Library |
| jo | JO Audio File |
| joy | Trackjoy GUS Tracker Song |
| jwf | Buzz Jacinth Waveform Audio |
| jwl | Buzz Jacinth Waveform Library |
| k25 | Kurzweil K2500 Data |
| k26 | Kurzweil K2600 Data |
| ka1 | Kawai K5000 Patch |
| kaa | Kawai K5000 Patch |
| kar | MIDI Karaoke Song |
| kat | Katorzer Music Composition |
| kfn | KaraFun Karaoke File |
| ki | Klystrack Instrument |
| kit | NI Battery Drum Kit |