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Getting started

This topic contains the following sections:

This guide will give a gentle introduction to how to start creating music with MIDI Gremlin.

Tip Tip

This guide goes somewhat in dept, not only explaining how, but also the what and why. If you just want to get started creating music, you can read [8c0c97d0-c968-4c15-9fe9-e8f3a443c50a] for a crash course.

Creating an Orchestra and an Instrument

The first step to playing music is creating an Orchestra and an Instrument.

All Orchestras require an IMidiOut interface. This interface is in most cases a WinmmOut that plays MIDI commands over Windows Multi Media dll, but it is possible to substitute it with something else.

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const int midiDeviceId = 0; //Most computers will only have this one.
const int beatsPerSecond = 60; //Tempo of the music. 60 beats per second 1 one beat equals 1 second.
IMidiOut output = new WinmmOut(midiDeviceId, beatsPerSecond);
Orchestra orchestra = new Orchestra(output);

Instrument piano = orchestra.AddInstrument(InstrumentType.BrightAcousticPiano);

Once you have created an Instrument we can test it by playing a single sound. If you are using WinmmOut and not another implementation of IMidiOut that sound should come out of your speakers. If it dosen't, check your audio setup.

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//Play a single sound
piano.Play(Tone.C, 1);
orchestra.WaitForFinished();

Normally you won't be sending Tones directly to an Instrument but it is the quickest way to get started.

Creating your first MusicObject

Now that we have a connection to your speakers, we can start creating some simple MusicObjects. MusicObjects are composite objects building a tree structure of music.

The first MusicObject we are going to use is the Note class. A Note is one of the fundemental MusicObject representing a single keypress.

Tip Tip

This is not quite true. A Note contains a Keystroke and a Pause. For more details, see Note documentation. For our pourposes, however, this is a quite reasonable abstraction.

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MusicObject longF = new Note(Tone.F, 1);
MusicObject shortF = new Note(Tone.F, 0.5);
MusicObject longA = new Note(Tone.A, 1);
MusicObject shortA = new Note(Tone.A, 0.5);
MusicObject longG = new Note(Tone.G, 1);
MusicObject shortG = new Note(Tone.G, 0.5);


Console.WriteLine("Press enter to play a single sound");
Console.ReadLine();
//We can play any of those on an instrument if we wish
piano.Play(shortG);
orchestra.WaitForFinished();

Once we have some pieces of music, we are going to use them to create larger pieces. These can be made as large as you wish.

Caution note Caution

Make sure not add a MusicObject to any of its own children. MidiGremlin does not detect this and parsing is going to cause a StackoverflowException if you try to play or transform it.

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//Create 2 smaller MusicObjects made out of the base pieces
MusicObject sequence1 = new SequentialMusicList(longF, shortA, longG, shortA);
MusicObject sequence2 = new SequentialMusicList(shortA, shortA, shortA, longA, shortF);

//Now create a bigger MusicObject made of those 2 smaller ones and one new
SequentialMusicList bigMusicObject = new SequentialMusicList(sequence1, sequence1, sequence2, new Note(Tone.D, 2));

//We can play this too
//We can play any of those on an instrument if we wish
Console.WriteLine("Press enter to play a longer sequence of sound");
Console.ReadLine();
piano.Play(bigMusicObject);
orchestra.WaitForFinished();
Using transformations to create variations

Finally we are going to look at transformations. Transformations allow you to copy a MusicObject while applying a function to all children of a specified type.

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//Make the 1st object a little lower on the scale, using a transform
int[] offsets = { 0, -3, -3, -2 };
bigMusicObject[1] = bigMusicObject[1].Select<Note>((x,y) => x.OffsetBy(Scale.MajorScale, offsets[y]));

//Play our final piece.
Console.WriteLine("Press enter to play \"Drømte mig en drøm i nat\", ");
Console.ReadLine();
piano.Play(bigMusicObject);
orchestra.WaitForFinished();

//You have just heard https://en.wikipedia.org/wiki/Dr%C3%B8mde_mik_en_dr%C3%B8m_i_nat
Using another Instrument

If a piano is not your cup of tea, playing on an other instrument is as simple as creating it and telling it what to play.

Caution note Caution

Due to the limitations of the MIDI standard, playing more than 15 normal instruments and 1 drum at the same time is going to result in an error.

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//Create a flute
Instrument flute = orchestra.AddInstrument(InstrumentType.Flute);




Console.WriteLine("Press enter to play \"Drømte mig en drøm i nat\" on a flute");
Console.ReadLine();
flute.Play(bigMusicObject);
orchestra.WaitForFinished();
All code used in this article
C#
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using System;
using MidiGremlin;

namespace GettingStarted
{
    class Program
    {
        static void Main(string[] args)
        {


            #region Orchestra
            const int midiDeviceId = 0; //Most computers will only have this one.
            const int beatsPerSecond = 60; //Tempo of the music. 60 beats per second 1 one beat equals 1 second.
            IMidiOut output = new WinmmOut(midiDeviceId, beatsPerSecond);
            Orchestra orchestra = new Orchestra(output);

            Instrument piano = orchestra.AddInstrument(InstrumentType.BrightAcousticPiano);
            #endregion

            #region SingleSound

            //Play a single sound
            piano.Play(Tone.C, 1);
            orchestra.WaitForFinished();

            #endregion

            #region MusicObjects
            MusicObject longF = new Note(Tone.F, 1);
            MusicObject shortF = new Note(Tone.F, 0.5);
            MusicObject longA = new Note(Tone.A, 1);
            MusicObject shortA = new Note(Tone.A, 0.5);
            MusicObject longG = new Note(Tone.G, 1);
            MusicObject shortG = new Note(Tone.G, 0.5);


            Console.WriteLine("Press enter to play a single sound");
            Console.ReadLine();
            //We can play any of those on an instrument if we wish
            piano.Play(shortG);
            orchestra.WaitForFinished();

            #endregion

            #region LargeMusicObject

            //Create 2 smaller MusicObjects made out of the base pieces
            MusicObject sequence1 = new SequentialMusicList(longF, shortA, longG, shortA);
            MusicObject sequence2 = new SequentialMusicList(shortA, shortA, shortA, longA, shortF);

            //Now create a bigger MusicObject made of those 2 smaller ones and one new
            SequentialMusicList bigMusicObject = new SequentialMusicList(sequence1, sequence1, sequence2, new Note(Tone.D, 2));

            //We can play this too
            //We can play any of those on an instrument if we wish
            Console.WriteLine("Press enter to play a longer sequence of sound");
            Console.ReadLine();
            piano.Play(bigMusicObject);
            orchestra.WaitForFinished();

            #endregion

            #region Transformation
            //Make the 1st object a little lower on the scale, using a transform
            int[] offsets = { 0, -3, -3, -2 };
            bigMusicObject[1] = bigMusicObject[1].Select<Note>((x,y) => x.OffsetBy(Scale.MajorScale, offsets[y]));

            //Play our final piece.
            Console.WriteLine("Press enter to play \"Drømte mig en drøm i nat\", ");
            Console.ReadLine();
            piano.Play(bigMusicObject);
            orchestra.WaitForFinished();

            //You have just heard https://en.wikipedia.org/wiki/Dr%C3%B8mde_mik_en_dr%C3%B8m_i_nat
            #endregion

            #region OtherInstrument
            //Create a flute
            Instrument flute = orchestra.AddInstrument(InstrumentType.Flute);




            Console.WriteLine("Press enter to play \"Drømte mig en drøm i nat\" on a flute");
            Console.ReadLine();
            flute.Play(bigMusicObject);
            orchestra.WaitForFinished();
            #endregion

            #region TransformToChords
            //Using Select<>() it's also possible to change the type of a MusicObject.
            ChordVariety minor = ChordVariety.Minor;
            MusicObject asChords = bigMusicObject.Select<Note>(n => minor.WithBaseTone(n.Keystroke.Tone, n.Pause.Duration));

            Console.WriteLine("Press enter to play \"Drømte mig en drøm i nat\" as minor.");
            Console.ReadLine();

            piano.Play(asChords);

            orchestra.WaitForFinished();
            #endregion



        }
    }
}
See Also