The midi/in device class consists of MIDI sequencers that are used for input. You access these devices by using the MIDI functions, which are described in the Platform Software Development Kit (SDK).

The lineGetID and phoneGetID functions fill a VARSTRING structure, setting the dwStringFormat member to the STRINGFORMAT_BINARY value and appending this additional member:

DWORD DeviceId;  // identifier of MIDI device

The DeviceId member is the identifier of a closed MIDI device. You use this identifier in a call to the midiInOpen function to open the device for input. You can use the resulting device handle to record MIDI data from the line or phone device.

For more information about the MIDI functions, see Multimedia Functions.