| x0v | Yamaha Motif XS Voice Data |
| x3a | Yamaha Motif XF Song Data |
| x3v | Yamaha Motif XF Voice Data |
| x3w | Yamaha Motif XF Waveform Data |
| x4a | Yamaha MOX6 All Audio Data |
| x4e | Yamaha MOX6 Editor Audio |
| x4v | Yamaha MOX6 Voice Data |
| x5a | Yamaha MX49 Library Data |
| x6v | Yamaha MOXF Voice Data |
| xad | eXotic ADlib Audio |
| xan | XANN Packer Audio Data |
| xann | XANN Packer Audio Data |
| xfs | eRacer Sound |
| xgc | Binary eXtended Genesis Music |
| xgm | eXtended Genesis Music |
| xi | FastTracker 2 Instrument |
| xiz | ZynAddSubFX Instrument File |
| xkr | Sing-Magic Karaoke Song |
| xm | FastTracker 2 Music Module |
| xma | Xbox 360 Native Audio |
| xmf | Extensible Music Format File |
| xmf0 | Extensible Music Format File |
| xmf1 | Extensible Music Format File |
| xmi | Extended MIDI Song |
| xms | XMS Tracker Module |
| xmz | FastTracker 2 Extended Module |
| xmz | ZynAddSubFX Master File |
| xopus | Exient XGS OPUS Audio Data |
| xp | FastTracker 2 Pattern |
| xpm | Akai MPC Software Program |
