| B | Music.MusicXml.Pitch |
| BackSlashedNoteHead | Music.MusicXml.Score, Music.MusicXml, Music.MusicXml.Simple |
| backup | Music.MusicXml.Simple |
| BackwardHook | Music.MusicXml.Score, Music.MusicXml, Music.MusicXml.Simple |
| bar | Music.MusicXml.Simple |
| bassClef | Music.MusicXml.Simple |
| beam | Music.MusicXml.Simple |
| BeamType | Music.MusicXml.Score, Music.MusicXml, Music.MusicXml.Simple |
| Beat | |
| 1 (Type/Class) | Music.MusicXml.Time, Music.MusicXml.Score, Music.MusicXml, Music.MusicXml.Simple |
| 2 (Data Constructor) | Music.MusicXml.Time, Music.MusicXml.Score, Music.MusicXml, Music.MusicXml.Simple |
| BeatType | |
| 1 (Type/Class) | Music.MusicXml.Time, Music.MusicXml.Score, Music.MusicXml, Music.MusicXml.Simple |
| 2 (Data Constructor) | Music.MusicXml.Time, Music.MusicXml.Score, Music.MusicXml, Music.MusicXml.Simple |
| BeginBeam | Music.MusicXml.Score, Music.MusicXml, Music.MusicXml.Simple |
| beginBeam | Music.MusicXml.Simple |
| beginCresc | Music.MusicXml.Simple |
| beginDim | Music.MusicXml.Simple |
| beginGliss | Music.MusicXml.Simple |
| beginSlide | Music.MusicXml.Simple |
| beginSlur | Music.MusicXml.Simple |
| beginTie | Music.MusicXml.Simple |
| Bend | Music.MusicXml.Score, Music.MusicXml, Music.MusicXml.Simple |
| brace | Music.MusicXml.Simple |
| Bracket | Music.MusicXml.Score, Music.MusicXml, Music.MusicXml.Simple |
| bracket | Music.MusicXml.Simple |
| BreathMark | Music.MusicXml.Score, Music.MusicXml, Music.MusicXml.Simple |
| breathMark | Music.MusicXml.Simple |