| Abbreviation | Definition |
|---|---|
| SIJ | Scumbags in Japan |
| SILO | South Island Light Orchestra |
| SIM | School for Improvisational Music |
| SIMA | South Indian Music Academy |
| SIMC | Sendai International Music Competition |
| SIMC | Summer Instrumental Music Camp |
| SIMS | Selina International Music Summit |
| SIN | Safety In Numbers |
| SIP | Solo In Place |
| SIPE | Soldier Integrated Protective Ensemble |
| SIPM | School of Indian Percussion and Music |
| SIR | String Instrument Repair |
| SIR | Studio Instrument Rental |
| SIS | Self Injury Song |
| SISO | Southern Illinois Symphony Orchestra |
| SIT | Stay In Tune |
| SITB | Somewhere In The Between |
| SJAM | San Jose Academy of Music |
| SJK | Smokin Joe Kubek |
| SJMO | Smithsonian Jazz Masterworks Orchestra |