Windows.Devices.Midi2.Utilities.Sequencing
This namespace holds music on a timeline, called a sequence, and a player that sends it out. It isn’t tied to any file format, on purpose. A Standard MIDI File read with MidiStandardFileReader gives you a MidiSequence, and so does an app that builds one itself with MidiSequenceBuilder.
MidiSequencePlayer gives its messages to the service with a timestamp on each one, and lets the service send them at the right time. It doesn’t wake up to send each one itself. That’s what keeps playback steady when the PC is busy, and it’s why a sequence has to be prepared before playback starts.
A sequence isn’t a collection of message objects. It’s a way to reach the data it stores. Real files can have millions of events, so the busiest parts of a sequence are never handed to your app one item at a time:
IVectorView collections. Each is built once and kept.FillNotesInTickRange. So drawing a frame takes one call, not one call per note.If you’re drawing a piano roll, this difference decides whether your app is fast or too slow to use.
Click or tap the type name to view more details.
| Type | Description |
|---|---|
| MidiSequence | Music on a timeline, ready to be played or drawn |
| MidiSequenceBarPosition | Where a tick falls in bars and beats |
| MidiSequenceBuilder | Builds a sequence in memory, without a file |
| MidiSequenceFormat | How the tracks in a sequence relate to each other |
| MidiSequenceLyricLine | Lyric syllables reassembled into a line you can display |
| MidiSequenceNote | A note with both ends already paired |
| MidiSequencePlayer | Plays a sequence to one or more endpoints |
| MidiSequencePlayerPosition | Everything a transport display needs, read in one call |
| MidiSequencePlayerState | What a sequence player is currently doing |
| MidiSequenceTempoChange | One tempo change in a sequence, in both the file's terms and in beats per minute |
| MidiSequenceTextEvent | A piece of text carried in a sequence, with the tick it belongs to |
| MidiSequenceTextKind | What kind of text a sequence text event carries |
| MidiSequenceTimeSignature | One time signature change in a sequence |
| MidiSequenceTimingMode | Whether the ticks in a sequence are musical or measured in real time |
| MidiSequenceTrack | One track of a sequence, and what the file said about it |
| MidiSequenceTrackRouting | Where one track's messages are sent during playback |
Windows MIDI Services is an open source project with all source available on GitHub. We have a great community on Discord as well. Between GitHub and Discord, you should find the information you are looking for.
