Código para reproducir notas musicales mediante midiOutShortMsg

Hola

Quiero compartir este programa que he desarrollado.

Se trata de un teclado musical, un piano que utiliza el parche Standard MIDI Patch Assignments del MIDI Manufacturers Association (MMA) con 128 sonidos de instrumentos diferentes.

Standard MIDI Patch Assignments

Permite tanto tocar con el ratón como con el teclado del ordenador.

Puedes descargarte el código aquí:

Musical_Keyboard.zip

*Elige el botón de la derecha, el que pone 'Descargar con el navegador'

Si lo prefieres puedes hacer simplemente un copia y pega en un nuevo proyecto 'Aplicación de Windows Form'

No necesitas crear controles, tan solo deja todo en blanco en el editor de código de Form1.vb, y pegas este código:

Código

'//////////////////////////////
'//    Date: 13/06/2016      //
'//  Programmed by LEKIM     //
'//////////////////////////////
 
Option Strict On
Imports System.Runtime.InteropServices
Imports System.Text
Imports System.Security
 
Public Class Form1
    Dim lblMuscKey(61) As Label
    Dim lblInstruments(127) As Label
    Dim lblOctave(5) As Label
    Dim FlLayPanel As FlowLayoutPanel
    Dim lblTitle As New Label
    Dim ttip As New ToolTip
    Dim numKeysBlack() As Integer = _
        {2, 4, 7, 9, 11, 14, 16, 19, 21, 23, 26, 28, 31, _
         33, 35, 38, 40, 43, 45, 47, 50, 52, 55, 57, 59}
    Dim numKeysWhite() As Integer = _
        {1, 3, 5, 6, 8, 10, 12, 13, 15, 17, 18, 20, 22, _
         24, 25, 27, 29, 30, 32, 34, 36, 37, 39, 41, 42, _
         44, 46, 48, 49, 51, 53, 54, 56, 58, 60, 61}
    Dim hMidiOut As IntPtr
    Dim intMsg As Integer
    Dim Msg As NativeMethods.MidiMsg
    Dim Octave As Byte = 1 'Octave from where begins the first key of the musical keyboard
    Dim ListKeyPress As New List(Of Integer)
    Dim VolumeKey As Byte = 127 'min=0; max=127
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        CreateMusicalKeyBoard()
        CreatePanelInstruments()
        CreateOctaveButtons()
        With lblTitle
            .Text = "Standard MIDI Patch Assignments"
            .BackColor = Color.Transparent
            .ForeColor = Color.WhiteSmoke
            .Font = New Font("Arial", 20, FontStyle.Bold)
            .TextAlign = ContentAlignment.MiddleLeft
            .Size = CType(New Point(470, 40), Drawing.Size)
            .Location = New Point(5, 5)
        End With
 
        With Me
            .Controls.Add(lblTitle)
            .KeyPreview = True
            .BackColor = System.Drawing.Color.FromArgb(40, 40, 40)
            .Size = CType(New Point(835, 440), Drawing.Size)
            .Text = "Demo Musical Keyboard"
            .MaximizeBox = False
            .FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle
            .StartPosition = FormStartPosition.CenterScreen
            .SetBounds(CInt((Screen.PrimaryScreen.Bounds.Width - .Width) / 2),
                       CInt((Screen.PrimaryScreen.Bounds.Height - .Height) / 2) - 50,
                       .Width, .Height)
        End With
 
        'Show a tooltip message
        ttip.AutoPopDelay = 2000
        ttip.InitialDelay = 1000
        ttip.ReshowDelay = 500
        For I As Integer = 1 To 5
            ttip.SetToolTip(Me.lblOctave(I), "Octave")
        Next
 
 
        NativeMethods.midiOutOpen(hMidiOut, _
                                  NativeMethods.MIDI_MAPPER, CType(0, IntPtr), _
                                        CType(0, IntPtr), NativeMethods.CALLBACK_NULL)
    End Sub
    Private Sub Form1_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown
        If ListKeyPress.Contains(e.KeyCode) = True Then Exit Sub ' Key is already pressed
        If Key(e.KeyCode) = 0 Then Exit Sub
        PlayMusicalNote(CByte(Key(e.KeyCode)), VolumeKey, Octave)
        ListKeyPress.Add(e.KeyCode)
    End Sub
    Private Sub Form1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyUp
 
        OffMusicalNote(CByte(Key(e.KeyCode)), Octave)
        ListKeyPress.Remove(e.KeyCode)
        Try
            If numKeysWhite.Contains(Msg.Note) Then
                lblMuscKey(Msg.Note).BackColor = Color.White
            Else
                lblMuscKey(Msg.Note).BackColor = Color.Black
            End If
        Catch ex As Exception
        End Try
 
    End Sub
 
#Region "Octave Buttons"
    Sub CreateOctaveButtons()
        Dim pOct As New Point(30, 265)
        Dim inc As Integer = 0
        For I = 1 To 5
            lblOctave(I) = New Label
            With lblOctave(I)
                .Text = CStr(I)
                .Font = New Font("Arial", 10, FontStyle.Bold)
                .Size = CType(New Point(20, 20), Drawing.Size)
                .BorderStyle = BorderStyle.FixedSingle
                .Location = New Point(pOct.X + inc, pOct.Y)
                .ForeColor = System.Drawing.Color.FromArgb(120, 120, 120)
                .BackColor = System.Drawing.Color.FromArgb(20, 20, 20)
                .TextAlign = ContentAlignment.MiddleCenter
                AddHandler .MouseDown, AddressOf lblOctave_MouseDown
                AddHandler .MouseEnter, AddressOf lblOctave_MouseEnter
                AddHandler .MouseLeave, AddressOf lblOctave_MouseLeave
            End With
            inc = inc + 19
            Me.Controls.Add(lblOctave(I))
        Next
 
        lblOctave(1).BackColor = System.Drawing.Color.FromArgb(150, 150, 150)
        lblOctave(1).ForeColor = System.Drawing.Color.FromArgb(10, 10, 10)
 
    End Sub
    Private Sub lblOctave_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
        Dim Index As Integer = Array.IndexOf(lblOctave, sender)
        For I As Integer = 1 To 5
            lblOctave(I).BackColor = System.Drawing.Color.FromArgb(20, 20, 20)
            lblOctave(I).ForeColor = System.Drawing.Color.FromArgb(120, 120, 120)
        Next
        lblOctave(Index).BackColor = System.Drawing.Color.FromArgb(150, 150, 150)
        lblOctave(Index).ForeColor = System.Drawing.Color.FromArgb(10, 10, 10)
 
        Octave = CByte(Index)
    End Sub
    Private Sub lblOctave_MouseEnter(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim Index As Integer = Array.IndexOf(lblOctave, sender)
        Cursor = Cursors.Hand
    End Sub
    Private Sub lblOctave_MouseLeave(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim Index As Integer = Array.IndexOf(lblOctave, sender)
        Cursor = Cursors.Default
    End Sub
#End Region
 
#Region "Panel of Instruments"
    ''' <summary>
    ''' Create a panel of instruments
    ''' </summary>
    ''' <remarks></remarks>
    Public Sub CreatePanelInstruments()
        FlLayPanel = New FlowLayoutPanel
        With FlLayPanel
            .AutoScroll = True
            .VerticalScroll.Visible = False
            .BorderStyle = BorderStyle.FixedSingle
            .Size = CType(New Point(808, 205), Drawing.Size)
            .Location = New Point(5, 50)
            .FlowDirection = FlowDirection.TopDown
            .BackColor = System.Drawing.Color.FromArgb(10, 10, 10)
        End With
        Me.Controls.Add(FlLayPanel)
 
        For I As Integer = 0 To lblInstruments.Count - 1
            lblInstruments(I) = New Label
            With lblInstruments(I)
                .Width = 155
                .Font = New Font("Arial", 8, FontStyle.Bold)
                .ForeColor = System.Drawing.Color.FromArgb(120, 120, 120)
                .BorderStyle = BorderStyle.FixedSingle
                .TextAlign = ContentAlignment.MiddleLeft
 
            End With
            FlLayPanel.Controls.Add(lblInstruments(I))
        Next (I)
 
        'Standard MIDI Patch Assignments 
        Dim strInstruments() As String = _
            {"000 Acoustic grand piano", "001 Bright acoustic piano", "002 Electric grand piano", "003 Honky-tonk piano",
             "004 Rhodes(piano)", "005 Chorused(piano)", "006 Harpsichord", "007 Clavinet", "008 Celesta",
             "009 Glockenspiel", "010 Music(box)", "011 Vibraphone", "012 Marimba", "013 Xylophone", "014 Tubular(bells)",
             "015 Dulcimer", "016 Hammond(organ)", "017 Percussive(organ)", "018 Rock(organ)", "019 Church(organ)",
             "020 Reed(organ)", "021 Accordion", "022 Harmonica", "023 Tango(accordion)", "024 Acoustic guitar (nylon)",
             "025 Acoustic(guitar(steel))", "026 Electric(guitar(jazz))", "027 Electric(guitar(clean))",
             "028 Electric(guitar(muted))", "029 Overdriven(guitar)", "030 Distortion(guitar)", "031 Guitar(harmonics)",
             "032 Acoustic bass", "033 Electric bass (finger)", "034 Electric bass (pick)", "035 Fretless bass",
             "036 Slap bass 1", "037 Slap bass 2", "038 Synth bass 1", "039 Synth bass 2", "040 Violin",
             "041 Viola", "042 Cello", "043 Contrabass", "044 Tremolo strings", "045 Pizzicato strings", "046 Orchestral harp",
             "047 Timpani", "048 String ensemble 1", "049 String ensemble 2", "050 Synth.strings(1)", "051 Synth.strings(2)",
             "052 Choir(Aahs)", "053 Voice(Oohs)", "054 Synth(voice)", "055 Orchestra(hit)", "056 Trumpet", "057 Trombone",
             "058 Tuba", "059 Muted(trumpet)", "060 French(horn)", "061 Brass(section)", "062 Synth.brass(1)",
             "063 Synth.brass(2)", "064 Soprano sax", "065 Alto sax", "066 Tenor sax", "067 Baritone sax", "068 Oboe",
             "069 English horn", "070 Bassoon", "071 Clarinet", "072 Piccolo", "073 Flute", "074 Recorder",
             "075 Pan flute", "076 Bottle blow", "077 Shakuhachi", "078 Whistle", "079 Ocarina", "080 Lead 1 (square)",
             "081 Lead 2 (sawtooth)", "082 Lead 3 (calliope lead)", "083 Lead 4 (chiff lead)", "084 Lead 5 (charang)",
             "085 Lead 6 (voice)", "086 Lead 7 (fifths)", "087 Lead 8 (brass + lead)", "088 Pad 1 (new age)",
             "089 Pad 2 (warm)", "090 Pad 3 (polysynth)", "091 Pad 4 (choir)", "092 Pad 5 (bowed)", "093 Pad 6 (metallic)",
             "094 Pad 7 (halo)", "095 Pad 8 (sweep)", "096 FX 1 (rain)", "097 FX 2 (soundtrack)", "098 FX 3 (crystal)",
             "099 FX 4 (atmosphere)", "100 FX 5 (brightness)", "101 FX 6 (goblins)", "102 FX 7 (echoes)", "103 FX 8 (sci-fi)",
             "104 Sitar", "105 Banjo", "106 Shamisen", "107 Koto", "108 Kalimba", "119 Bagpipe", "110 Fiddle", "111 Shanai2",
             "112 Tinkle Bell", "113 Agogo", "114 Steel Drums", "115 Woodblock", "116 Taiko Drum", "117 Melodic Tom",
             "118 Synth Drum2", "119 Reverse Cymbal", "120 Guitar fret noise", "121 Breath noise", "122 Seashore",
             "123 Bird tweet", "124 Telephone ring", "125 Helicopter", "126 Applause", "127 Gunshot"}
 
        For I = 0 To 127
            lblInstruments(I).Text = strInstruments(I)
        Next
        For I As Integer = 0 To lblInstruments.Count - 1
            AddHandler lblInstruments(I).MouseDown, AddressOf lblInstruments_MouseDown
        Next
 
    End Sub
    Private Sub lblInstruments_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
        Dim Index As Integer = Array.IndexOf(lblInstruments, sender)
        For I = 0 To lblInstruments.Count - 1
            lblInstruments(I).BackColor = Color.Transparent
            lblInstruments(I).ForeColor = System.Drawing.Color.FromArgb(120, 120, 120)
 
        Next
        lblInstruments(Index).BackColor = System.Drawing.Color.FromArgb(150, 150, 150)
        lblInstruments(Index).ForeColor = System.Drawing.Color.FromArgb(0, 0, 0)
        ChangeInstrument(Index)
    End Sub
#End Region
 
#Region "Musical Keyboard"
    ''' <summary>
    ''' Create the keys of the musical keyboard
    ''' </summary>
    ''' <remarks></remarks>
    Sub CreateMusicalKeyBoard()
        Dim wKeyWhite As New Point(22, 80)
        Dim wKeyBlack As New Point(12, 50)
        Dim PosKeyWhite As New Point(30, 300)
        Dim PosKeyBlack As New Point(25, 300)
 
        For Index As Integer = 1 To lblMuscKey.Count - 1
            lblMuscKey(Index) = New Label
            With lblMuscKey(Index)
                .BorderStyle = BorderStyle.FixedSingle
                Dim incWhiteKeyPosX As Integer
                'White keys
                If numKeysWhite.Contains(Index) Then
                    .Size = New Size(wKeyWhite)
                    .BackColor = Color.White
                    .Location = _
                        New Point(PosKeyWhite.X + incWhiteKeyPosX, PosKeyWhite.Y)
                    incWhiteKeyPosX = incWhiteKeyPosX + 21
                    .SendToBack() 'send to back
                End If
                'Black keys
                If numKeysBlack.Contains(Index) Then
                    .BackColor = Color.Black
                    .Size = New Size(wKeyBlack)
                    .Location = _
                        New Point(PosKeyBlack.X + incWhiteKeyPosX, PosKeyBlack.Y)
                End If
                Me.Controls.Add(lblMuscKey(Index))
                If numKeysBlack.Contains(Index) Then
                    lblMuscKey(Index).BringToFront()
                End If
 
                AddHandler .MouseDown, AddressOf lblMuscKey_MouseDown
                AddHandler .MouseUp, AddressOf lblMuscKey_MouseUp
                AddHandler .MouseMove, AddressOf lblMuscKey_MouseMove
                AddHandler .MouseLeave, AddressOf lblMuscKey_MouseLeave
            End With
 
        Next
 
 
    End Sub
    Private Sub lblMuscKey_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
        Dim Index As Integer = Array.IndexOf(lblMuscKey, sender)
        lblMuscKey(Index).BackColor = Color.Gray 'Change color of the key
        PlayMusicalNote(CByte(Index), VolumeKey, Octave)
    End Sub
    Private Sub lblMuscKey_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
        Dim Index As Integer = Array.IndexOf(lblMuscKey, sender)
        If numKeysWhite.Contains(Index) Then
            lblMuscKey(Index).BackColor = Color.White 'Change color of the key
        Else
            lblMuscKey(Index).BackColor = Color.Black 'Change color of the key
        End If
 
        OffMusicalNote(Index, Octave)
    End Sub
    Private Sub lblMuscKey_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
        Dim Index As Integer = Array.IndexOf(lblMuscKey, sender)
        Dim mPoint As New Point(Me.PointToClient(Cursor.Position).X, Me.PointToClient(Cursor.Position).Y)
        Dim X As Integer = mPoint.X
        Cursor = Cursors.Hand
        If X < CInt(lblMuscKey(Index).Left) Or
            X > (CInt(lblMuscKey(Index).Left) + _
                 CInt(lblMuscKey(Index).Width)) Then
            EventoUp()
            EventoDown()
        End If
 
    End Sub
    Private Sub lblMuscKey_MouseLeave(ByVal sender As Object, ByVal e As System.EventArgs)
        Cursor = Cursors.Default
    End Sub
#End Region
 
 
#Region "Play Sounds Functions"
    ''' <summary>
    ''' Play a musical note
    ''' </summary>
    ''' <param name="Note">Value of musical note</param>  
    ''' <param name="Volume">Volume musical note</param>
    ''' <param name="bOct">Octave</param>
    ''' <returns></returns>
    Public Function PlayMusicalNote(ByVal Note As Integer, ByVal Volume As Byte, ByVal bOct As Byte) As Boolean
        Note += 23 + (12 * bOct)
        intMsg = CInt(Volume * Convert.ToInt32(CStr(10000), 16) _
+ Note * Convert.ToInt32(CStr(100), 16) + NativeMethods.KeyOn)
 
        Return CBool(NativeMethods.midiOutShortMsg(hMidiOut, intMsg))
    End Function
    ''' <summary>
    ''' Off a musical note
    ''' </summary>
    ''' <param name="Note">Value of musical note</param>
    ''' <param name="bOct">Octave</param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Function OffMusicalNote(ByVal Note As Integer, ByVal bOct As Integer) As Boolean
        Note += 23 + (12 * bOct)
        intMsg = Note * Convert.ToInt32(CStr(100), 16) + NativeMethods.KeyOff
        Return CBool(NativeMethods.midiOutShortMsg(hMidiOut, intMsg))
    End Function
    ''' <summary>
    ''' Change the instrument
    ''' </summary>
    ''' <param name="instCode"></param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Function ChangeInstrument(ByVal instCode As Integer) As Boolean
        intMsg = instCode * Convert.ToInt32(CStr(100), 16) + NativeMethods.Instruments
        Return CBool(NativeMethods.midiOutShortMsg(hMidiOut, intMsg))
        Return Nothing
    End Function
#End Region
#Region "Computer keyboard keys"
    ''' <summary>
    ''' Assigning Computer keyboard keys
    ''' </summary>
    ''' <param name="keycode"></param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Function Key(ByVal keycode As Integer) As Integer
        Dim BlackHalfKey() As Keys = {Keys.W, Keys.E, Keys.T, Keys.Y, Keys.U}
        Dim WhiteHalfKey() As Keys = {Keys.A, Keys.S, Keys.D, Keys.F, Keys.G, Keys.H, Keys.J, Keys.K}
        Dim BassKey() As Keys = {Keys.Z, Keys.X, Keys.C, Keys.V, Keys.B, Keys.N, Keys.M, Keys.Oemcomma}
        Dim AltoKey() As Keys = {Keys.D1, Keys.D2, Keys.D3, Keys.D4, Keys.D5, Keys.D6, Keys.D7, Keys.D8}
 
        If BlackHalfKey.Contains(CType(keycode, Keys)) Or _
            WhiteHalfKey.Contains(CType(keycode, Keys)) Or _
            BassKey.Contains(CType(keycode, Keys)) Or _
             AltoKey.Contains(CType(keycode, Keys)) Then
            For I As Integer = 10 To 14
                If keycode = BlackHalfKey(I - 10) Then Msg.Note = CByte(numKeysBlack(I))
            Next
 
            For I As Integer = 14 To 21
                If keycode = WhiteHalfKey(I - 14) Then Msg.Note = CByte(numKeysWhite(I))
            Next
 
            For I As Integer = 0 To 7
                If keycode = BassKey(I) Then Msg.Note = CByte(numKeysWhite(I))
            Next
            For I As Integer = 28 To 35
                If keycode = AltoKey(I - 28) Then Msg.Note = CByte(numKeysWhite(I))
            Next
 
            lblMuscKey(Msg.Note).BackColor = Color.Gray
 
            Return Msg.Note
        Else
            Return 0
        End If
 
    End Function
#End Region
End Class
 
Module MouseEvents
    ''' <summary>
    ''' Simulate MouseDown the left mouse button
    ''' </summary>
    ''' <remarks></remarks>
    Public Sub EventoDown()
        NativeMethods.mouse_event(NativeMethods.MouseEventFlags.MOUSEEVENTF_LEFTDOWN, 0, 0, 0, 0)
    End Sub
    ''' <summary>
    ''' Simulate MouseUp the left mouse button
    ''' </summary>
    ''' <remarks></remarks>
    Public Sub EventoUp()
        NativeMethods.mouse_event(NativeMethods.MouseEventFlags.MOUSEEVENTF_MIDDLEUP, 0, 0, 0, 0)
    End Sub
 
End Module
 
<SuppressUnmanagedCodeSecurity()>
Friend NotInheritable Class NativeMethods
    Inherits Attribute
    Private Sub New()
    End Sub
 
#Region "API MIDI message"
    <DllImport("winmm.dll")>
    Public Shared Function midiOutOpen(ByRef lphMidiOut As IntPtr,
                                       ByVal uDeviceID As Integer,
                                       ByVal dwCallback As IntPtr,
                                       ByVal dwInstance As IntPtr,
                                       ByVal dwFlags As UInteger) As UInteger
    End Function
    <DllImport("winmm.dll")>
    Public Shared Function midiOutShortMsg(ByVal hMidiOut As IntPtr,
                                           ByVal dwMsg As Integer) As UInteger
    End Function
 
    <DllImport("winmm.dll")>
    Public Shared Function midiOutClose(ByVal hMidiOut As IntPtr) As Integer
    End Function
 
    <StructLayout(LayoutKind.Auto)> _
    Public Structure MidiMsg
        Dim status As Byte
        Dim Note As Byte
        Dim Volume As Byte
        Dim Data3 As Byte
    End Structure
    Public Const MIDI_MAPPER As Int32 = -1
    Public Const CALLBACK_NULL = &H0
    Public Const KeyOn As Integer = &H90
    Public Const KeyOff As Integer = &H80
    Public Const Instruments As Integer = &HC0
#End Region
 
#Region "API Mouse Events"
 
 
    <DllImport("user32.dll", CharSet:=CharSet.Auto)> _
    Friend Shared Sub mouse_event(ByVal dwFlags As UInteger, _
                                   ByVal dx As UInteger, _
                                   ByVal dy As UInteger, _
                                   ByVal dwData As UInteger, _
                                   ByVal dwExtraInfo As Integer)
    End Sub
 
    <Flags()> _
    Public Enum MouseEventFlags As UInteger
        MOUSEEVENTF_ABSOLUTE = &H8000
        MOUSEEVENTF_LEFTDOWN = &H2
        MOUSEEVENTF_LEFTUP = &H4
        MOUSEEVENTF_MIDDLEDOWN = &H20
        MOUSEEVENTF_MIDDLEUP = &H40
        MOUSEEVENTF_MOVE = &H1
        MOUSEEVENTF_RIGHTDOWN = &H8
        MOUSEEVENTF_RIGHTUP = &H10
        MOUSEEVENTF_XDOWN = &H80
        MOUSEEVENTF_XUP = &H100
        MOUSEEVENTF_WHEEL = &H800
        MOUSEEVENTF_HWHEEL = &H1000
    End Enum
 
#End Region
 
 
End Class

CÓDIGO BÁSICO PARA REPRODUCIR SONIDOS MIDI

Crea un Button, y pegas esto. Al pulsar el botón se escucha un sonido C2 (Do 2ª escala), que su valor es 47.

Código

 
Option Strict On
Imports System.Runtime.InteropServices
Imports System.Security
 
Public Class Form1
    Dim hMidiOut As IntPtr
    Dim intMsg As Integer
    Dim msg As New NativeMethods.MidiMsg
 
    Private Sub Form1_FormClosed(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosedEventArgs) Handles Me.FormClosed
        'Cierra los mensajes midi
        NativeMethods.midiOutClose(hMidiOut)
    End Sub
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'Abre los mensajes midi
        NativeMethods.midiOutOpen(hMidiOut, NativeMethods.MIDI_MAPPER,
                         CType(0, IntPtr), CType(0, IntPtr),
                         NativeMethods.CALLBACK_NULL)
 
        'Cambiar instrumento
        Dim MyInstr As Integer = 1 'min:0 (piano) ; max:127 (Gunshot)
        intMsg = MyInstr * Convert.ToInt32(CStr(100), 16) + NativeMethods.Instruments
        NativeMethods.midiOutShortMsg(hMidiOut, intMsg)
    End Sub
 
    Private Sub Button1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Button1.MouseDown
        'Reproduce un sonido los mensajes midi
        msg.status = NativeMethods.KeyOn
        msg.Volume = 127
        msg.Note = 47 '<---Sonido
        intMsg = msg.Volume * Convert.ToInt32(CStr(10000), 16) + _
            msg.Note * Convert.ToInt32(CStr(100), 16) + _
            msg.status
        NativeMethods.midiOutShortMsg(hMidiOut, intMsg)
    End Sub
 
    Private Sub Button1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Button1.MouseUp
        'Apaga el sonido al soltar el botón 
        '**El sonido debe ser el mismo que el que se quiere apagar 
        msg.status = NativeMethods.KeyOff
        msg.Volume = 0
        msg.Data3 = 0
        msg.Note = 47 '<---Sonido
        intMsg = msg.Volume * Convert.ToInt32(CStr(10000), 16) _
            + msg.Note * Convert.ToInt32(CStr(100), 16) + _
            msg.status
        NativeMethods.midiOutShortMsg(hMidiOut, intMsg)
    End Sub
End Class
 
 
 
<SuppressUnmanagedCodeSecurity()>
Friend NotInheritable Class NativeMethods
    Inherits Attribute
    Private Sub New()
    End Sub
 
#Region "API MIDI message"
    <DllImport("winmm.dll")>
    Public Shared Function midiOutOpen(ByRef lphMidiOut As IntPtr,
                                       ByVal uDeviceID As Integer,
                                       ByVal dwCallback As IntPtr,
                                       ByVal dwInstance As IntPtr,
                                       ByVal dwFlags As UInteger) As UInteger
    End Function
    <DllImport("winmm.dll")>
    Public Shared Function midiOutShortMsg(ByVal hMidiOut As IntPtr,
                                           ByVal dwMsg As Integer) As UInteger
    End Function
 
    <DllImport("winmm.dll")>
    Public Shared Function midiOutClose(ByVal hMidiOut As IntPtr) As Integer
    End Function
 
    <StructLayout(LayoutKind.Auto)> _
    Public Structure MidiMsg
        Dim status As Byte
        Dim Note As Byte
        Dim Volume As Byte
        Dim Data3 As Byte
    End Structure
    Public Const MIDI_MAPPER As Int32 = -1
    Public Const CALLBACK_NULL = &H0
    Public Const KeyOn As Integer = &H90
    Public Const KeyOff As Integer = &H80
    Public Const Instruments As Integer = &HC0
#End Region
 
End Class

Espero que disfrutéis del programa.

No soy un programador experto así que supongo que los más avispados veréis cosas corregibles.

Me he visto obligado a usar APIs. He estado buscando la forma de no tener que usarlo y usar puro código .NET, pero no lo he conseguido. A no ser que use mi propia biblioteca MIDI de sonidos.

[DESLIZANDO EL CURSOR]
He preguntado en varios sitios incluido aquí como crear el efecto de arrastrar el dedo por las teclas de un piano usando el puntero del ratón y con puro código NET. Pero no he tenido éxito, por ahora.

Como alternativa, de nuevo me he visto obligado a usar llamada API. La razón es que cuando pulsas una tecla del piano y mantienes pulsado el botón izquierdo al pasar a otra tecla se mantiene el evento de la tecla inicial ignorando por completo el hecho de que el puntero se haya en una nueva tecla. Con la imposibilidad de usar MouseEnter, ya que el que trabaja es el evento MouseEnter de la primera tecla. Usando Mouse_Event emulo la acción de soltar el botón, aunque en realidad aun lo tenga pulsado justo al entrar en la otra tecla. De nuevo emulo el evento de pulsar y la nueva tecla captura el evento. Es fácil conseguirlo con elementos que no forma parte de una matriz, pero se complica al usar un array de controles. Por esta razón he tenido que usar Mouse_Event.

S2s