| jbm | JBM Adlib Music Data |
| jcb | JCB-JCBrooke Music Module |
| jge | Roland Juno-G JGE Data |
| jgl | Roland Juno-G JGL Library |
| jo | JO Audio File |
| jo-7z | jo Audio |
| joy | Trackjoy GUS Tracker Song |
| jwf | Buzz Jacinth Waveform Audio |
| jwl | Buzz Jacinth Waveform Library |
| jxx | Yamaha SY77 Audio Data |
| k25 | Kurzweil K2500 Data |
| k26 | Kurzweil K2600 Data |
| ka1 | Kawai K5000 Patch |
| kaa | Kawai K5000 Patch |
| kam | Meragana Karaoke Data |
| kar | MIDI Karaoke Song |
| kat | Katorzer Music Composition |
| kdt | Konami KDT1 Song |
| keyboard | Amaya Keyboard Configuration Data |
| kfn | KaraFun Karaoke File |
| kft | Korg T1 Wave Data |
| ki | Klystrack Instrument |
| kit | NI Battery Drum Kit |
| kls | Kenwood HD60GD9 Lossless Audio |
| kmp | Korg Trinity Keymap |
| kmp3 | TKaraoke Karaoke MP3 Audio |
| korg | Korg Trinity Sample |
| koz | Audiokoz Music |
| kr1 | Kurzweil K2000 Split Data |
| kr2 | Kurzweil K2000 Split Data |
