| Abbreviation | Definition |
|---|---|
| IP | Iambic Pentameter |
| IPB | Indo Pakistani Band |
| IPBA | Irish Pipe Band Association |
| IPEM | Institute For Psychoacoustics And Electronic Music |
| IPEW | International Percussion Ensemble Week |
| IPO | Illinois Philharmonic Orchestra |
| IPP | Instantly Prepared Piano |
| IPRMS | Immortal Performances Recorded Music Society |
| IRC | International Rostrum of Composers |
| IRL | It's Right Left |
| IRMA | Irish Recorded Music Association |
| IRS | Italian Rhythm Section |
| IRTE | Improvisational Repertory Theatre Ensemble |
| ISAM | Institute for Studies in American Music |
| ISB | Incredible String Band |
| ISB | Independent Side Band |
| ISB | International Staff Band |
| ISB1 | Inspire Strikes Back part 1 |
| ISB2 | Inspire Strikes Back part 2 |
| ISBQ | Irreducible Shear Band Quad |