Audio Recording

If you are working in Linux/Ubuntu audio production environment, you might be interested in converting MP3 files to Midi files. This tutorial will illustrate technical processes on how to produce a MIDI version of an MP3 file. However before proceeding, take note of the following limitations:

1.) The MIDI version will be a faithful reproduction of an MP3 version (still not 100%) if there is only one musical instrument in the MP3 file (e.g. only a piano track). So for example, if you have a guitar solo recording in MP3 and you would like to convert that to MIDI; then it will be accurately reproduced. However, if you have an MP3 file consisting of different instruments (vocals, guitars, piano, drums), it will never be accurately reproduced and it will be far from the original. So to get the best MIDI conversion, is to convert a solo recording of an instrument to a MIDI version.

2.) The recording must be very clean, if there are some obvious noise, then it can affect the quality of the MIDI conversion because the source audio file is already noisy. You might want to learn the common causes of noise in recordings and the solutions.

The Conversion Steps

Step1.) Download AmazingMIDI here: http://www.pluto.dti.ne.jp/~araki/amazingmidi/

Step2.) Download the installer to your Ubuntu Desktop. The installer is an .exe file (azmid170.exe for example).

Step3.) Since this software runs only in Windows. You need Wine to be installed in your Ubuntu before you can install this program. If you do not have Wine installed, you can refer to the step 1 of this tutorial on installing Voxengo R8brain in Linux

If you are not using Linux, simply install the exe file directly in Windows and follow the succeeding steps below.

Step4.) Once you have a fully working Wine installation. Go to the Ubuntu Desktop and double click the installer (e.g azmid170.exe). It will then launched the installation screen. Follow the procedure until it is completed.

Step5.) Confirm if you have successfully installed AmazingMIDI. Go to Applications – Wine – Programs , make sure you see an entry “AmazingMIDI” as one of your Wine programs.

Step6.) Take note that AmazingMIDI can only convert WAV file to MIDI files. So you need to convert MP3 files to WAV files first. This can be done very easily using Audacity.

Note: Make sure that the source WAV file is in 16-bit/44.1KHz format. You can check its properties in Audacity. If its not in the correct format, e.g. the WAV file is in 24-bit or in different sample rate. You need to run voxengo R8brain sample rate converter. And convert the bit depth and sample rate of the WAV file to 16-bit/44.1KHz. Set the quality to very high.

Voxengo R8brain natively runs in Windows operating system. So you do not need Wine to run this Windows.

Step7.) Now that your MP3 audio is now converted to WAV audio, you are now ready to convert this WAV audio file to a MIDI file using AmazingMIDI. Launch this program by going to Applications – Wine – Programs – AmazingMIDI – AmazingMIDI. You will then see below:

Step8.) Let’s convert this guitar solo (in WAV) to MIDI file.
Download this sample WAV file.
(Guitar performance credit: Emerson Maningo)

What it sounds like in MP3?

In the AmazingMIDI “Tone File”; set it to sine.wav, locate this sine.wav in your Wine directory (a Windows simulation environment), e.g here; C:\Program Files\AmazingMIDI\sine.wav
In the Input File, this is the actual wav file you are converting; for example sampleguitar.wav, this is found in your Ubuntu Desktop.

The output file will be automatically provided, if you completed assigning the Input file path.

Step9.) Finally click “Transcribe”. For best results in converting a solo instrument (e.g guitar but this settings might be different for other instruments so feel free to experiment) set the following:

Minimum analysis: -40dB (this will ignore the quite passages)
Minimum relative: -40dB
Leave others at its default settings.

Step10.) Click Start, and then go the path where the MIDI file has been located (as provided by the output file path in AmazingMIDI). Copy and paste it to your Ubuntu Desktop.

Step11.) Now that everything is set; try to play midi using timidity midi sequencer which is your MIDI player in Ubuntu.

What this MIDI file sounds like?

As what you have noticed, it is not perfectly reproduced; there are some offbeats and out of placed notes. This is due to the dynamic nature of the guitar sound which is not perfectly suitable for MIDI conversion.The best scenario could be an original piano recording (in WAV) to a piano based MIDI, as our example is using a guitar WAV file to a MIDI.

Content last updated on March 28, 2012