A direct answer: Yes, .mid is a standard file extension for MIDI data; it is the conventional, official extension used for Standard MIDI Files that encode MIDI events and are used to transfer musical data between programs and devices. Details to help clarify:
- What MIDI files contain: Standard MIDI Files (SMF) store sequences of MIDI events and timing information, organized into chunks (a header and one or more track chunks). The header defines the file format, timing, and number of tracks; each track chunk contains the actual MIDI events for one channel or part. This structure is described in MIDI specifications and common references.
- File formats and types: SMF files come in two main types—Type 0 (single multi-channel track) and Type 1 (multiple separate tracks that are synchronized). The file begins with a header chunk (MThd) followed by one or more track chunks (MTrk). The extensions used for these files are typically .mid or slightly less commonly .midi, both referring to the same standard MIDI data.
- Alternative extensions: Some systems historically use .midi as an alternative to .mid, but they both represent the same MIDI data format. In most contexts, software and hardware recognize .mid as the standard extension.
If you’re curious about practical usage:
- Opening: Most digital audio workstations (DAWs), notation software, and MIDI hardware can open .mid files and map the contained events to virtual instruments or hardware synthesizers.
- Compatibility: Because the format is widely supported, .mid files are a reliable interchange format for sharing musical arrangements, arrangements, and performance data across platforms.
If you want, I can tailor this to a specific context (e.g., which programs natively support .mid on Windows/macOS, or how to distinguish Type 0 vs Type 1 files in practice).
