| ID | Title  | Author | Language | Number of records | Number of melodies |
|---|---|---|---|---|---|
| 303 | Orbis salus oritur | Anonymous | Latin | 0 | 0 |
| 521 | Organica gaudia | Anonymous | Latin | 0 | 0 |
| 99 | Oro mater castitatis | Anonymous | Latin | 0 | 0 |
| 752 | Ortum Christi sidere | Anonymous | Latin | 0 | 0 |
| 704 | Ortum floris cantitemus | Anonymous | Latin | 0 | 0 |
| 304 | Os almi nam te legati | Anonymous | Latin | 0 | 0 |
| 82 | Ostende virgo pia | Anonymous | Latin | 1 | 0 |
| 398 | Otče Bože všemohúcí | Anonymous | Czech | 2 | 1 |
| 917 | Otče náš jenž jsi na nebesiech Otče nass genz gssi na nebesiech | Anonymous | Czech | 0 | 1 |
| 28 | Otep myrry Otep myrhy | Anonymous | Czech | 1 | 1 |
| 589 | Padnúc na svá kolena | Anonymous | Czech | 0 | 1 |
| 842 | Pán Ježíš narozený - Tři králové - Pán Ježíš narozený | Anonymous | Czech | 0 | 2 |
| 841 | Pán Ježíš narozený - Tři králové - Zdrávna prorokové | Anonymous | Czech | 0 | 2 |
| 599 | Pán Ježíš náš spasitel | Anonymous | Czech | 0 | 1 |
| 600 | Pána Ježíše vzkříšenie | Anonymous | Czech | 0 | 1 |
| 590 | Pane bože buď při nás | Anonymous | Czech | 0 | 1 |
| 591 | Pane bože my k tobě voláme | Anonymous | Czech | 0 | 1 |
| 271 | Pangamus melos gloriae plebs | Anonymous | Latin | 0 | 0 |
| 272 | Pangamus melos gloriae regi | Anonymous | Latin | 0 | 0 |
| 39 | Pangant odas pariter | Anonymous | Latin | 1 | 1 |
