midiOutOpen

C# Signature:

[DllImport("winmm.dll")]
    static extern uint midiOutOpen(out IntPtr lphMidiOut, uint uDeviceID, IntPtr dwCallback, IntPtr dwInstance, uint dwFlags);

VB Signature:

<DllImport("winmm.dll")> Shared Function midiOutOpen(ByRef lphMidiOut As IntPtr, ByVal uDeviceID As UInteger, ByVal dwCallback As IntPtr, ByVal dwInstance As IntPtr, ByVal dwFlags As UInteger) As UInteger
    End Function