 AKoff Music Composer   Version 1.45

This program recognizes single instrument polyphonic music from microphone

(other WAVE input or file) and converts it into MIDI sequences (tracks).

CONTENTS:

About Music Recognition

What is AKoff Music Composer

Playing MIDI files

Main Audio Settings

Recording MIDI tracks

Improving Recognition results

Frequently Asked Questions

System Requirements

How to Register

© 1998,1999 AKoff Sound Labs, Inc.

E-mail: contacts@akoff.com

WWW: www.akoff.com


About Music Recognition

In few words music recognition is mathematical analysis of audio signal (usually in WAVE format) and its conversion into musical notation (usually in MIDI format). The difference consists in the representation of sound and music. The WAVE format is a digital recording of any sound (including speech) and MIDI format is principally sequence of notes, i.e. it is high level format. The relations between them approximately the same as between speech and printed text.

There are many audio formats, for example:

•	Windows PCM waveform (WAV)

•	Microsoft ADPCM waveform (WAV)

•	Sound Blaster voice file format (VOC)

•	Apple AIFF format (AIF, SND)

•	Raw PCM Data (PCM)

•	RealAudio (RA)

•	MPEG Layer (MP2, MP3)

•	and others

They differ from each other by compression algorithms of digital signals and can be refered to one group. The conversion from one format into another is very simple. There are many sound editors which allow to do this. The most natural format is Windows PCM waveform (WAV) which represents digital signals without any compression and without loss of quality.

Various musical formats represent extensions of Standard MIDI format (MID). Format conversion in the given group also is a simple task. But only conversion from Standard MIDI format is possible without loss of any information.

MIDI to WAV Conversion. MIDI format will be easily transformed to WAV format. You can play MIDI file in an appropriate player and record reproduced music in any sound editor. The size of WAV file will be more bigger than same music file represented in MIDI format. The quality of music will be determined by MIDI capabilities of your sound card and professionalism of the musician noting given MIDI file. There are many programs which transfer MIDI files in WAV format using only WAV output of your sound card and their own timbres of MIDI instruments. These programs allow to listen MIDI with high quality even on sound cards without MIDI support.

The reconversion from WAV into MIDI is music recognition problem which until now has not a qualitative solution. For comparison, the problem of recognition of printed text entered from the scanner is solved on 99% - it is an average exactitude of recognition of the programs of given class. The programs of speech recognition already work with an exactitude 80-90 %, whereas the sparse systems of music recognition work with an exactitude 70-80 % but only for single voice melody. For polyphonic music the exactitude is even lower. The variety of musical timbres, harmonic constructions and transitions is so great that, for example, there will be no computational capabilities of all computers of the world to recognize musical score of a symphonic orchestra!


What is AKoff Music Composer

Composer analyzes in real time a stream of audio signals from WAVE input of your sound card or from Windows PCM file (*.WAV). It can be sound from microphone, linear input or audio CD. For correct choice of input source of sound and set-up record level, read section Main Audio Settings.

Composer recognizes polyphonic music with one instrument or voice. This means you won't get the appropriated results if you try to record more than one instrument playing at the same time. Moreover, your voice and instruments have various timbres and complicated harmonic components, therefore the quality of recognition depends on the concrete instrument or singing style! Also the recognition is influenced by quality of your sound card and microphone. To get better results read section Improving Recognition results.

The complicated mathematical algorithms of the analysis of digital signals require a great amount of calculations and consequently fast computer. In real time Composer reliably works only on processors Pentium 133 and higher. On weaker machines the incorrect work or dead halt of the program is possible which is removed through pressing Ctrl-Alt-Del keys.

During recognition the recorded notes are automatically shown on the graphic keyboard in red color and are remembered in memory. After stop of recording you can play the obtained melody. You can also select the instrument, change octave and also try to correct musical scale. You can read about recording in the section Recording MIDI tracks. Further you can add the recorded track to the common list of MIDI tracks and then save generated MIDI file. The last two features are accessible only in the registered version.

If some notes are recognized incorrectly, you can open the saved file in any MIDI editor and manually correct your score. If you have MIDI keyboard, it will be easier to score music playing on the keyboard and using any MIDI editor. But if you aren't musician, Composer will help you to record your own melody in a popular musical MIDI format using only your voice!


Playing MIDI files

You can open MIDI files, play them, display the set of instruments used in the song, their volume and balance, change all these attributes and also record new tracks.

MIDI tracks aren't recording from MIDI keyboard but recognizing in real time from WAVE input (microphone, CD, line). You can whistle, sing, play guitar, piano, flute etc. with your microphone, Composer will automatically recognize and score your music and create standard MIDI sequences.

Playing Standard MIDI file

You can Open [image] standard MIDI files (*.mid) and Play [image] them.

If you click on Stop [image] button playing stopped and music position returned to the beginning.

You can Loop [image] music, Pause [image] it and set music position using Trackbar

  View Track List

If you click on View Track List button you can show or hide the list of MIDI tracks.

Here you can turn On/Off each track or Solo individual track.

You can also change Name, Instrument, Volume and Balance of each track.

  Mixer Settings

Click on Volume Control button and the default volume control dialog is opened (standard Window’s application SNDVOL32.EXE in Windows Directory).

  Delete Track

To delete a track you must select it as Solo and click on Delete button.

  Create new MIDI file

  Open Record track window

Read section Recording MIDI tracks.


Recording MIDI tracks

  Opening Record MIDI track window

If you can’t open Record track window this usually means that Composer has been unable to find the WAVE Input device. To check whether the device is installed, open Control Panel / Multimedia / Audio. There should be accessible even one input device. Also make sure that your sound system is functioning properly (read section Main Audio Settings).

Record | Stop button

To start recording click on Record button and begin singing or playing. To stop recording click on this button another time. The amount of recorded notes is mapped at the Notes field and recorded time – at the Time field. Note that if you click on Record button next time all previously recorded notes will be erased. To save them you must click on Add track button.

WAVE file button

To start conversion from WAVE file click on this button and select a file to convert. Composer works with Windows PCM files: mono or stereo; 11025 or 22050 or 44100  hz; 16 or 8 bits.

Sens (Record level and Sens threshold)

During recording at Sens bar you can see record level in decibels (dB). You must adjust Sens threshold (sensitivity) using Sens slider so that maximum record level will be more than sensitivity and mimimum level will be less. The notes will be well recognized only when the level of useful signal (while singing) exceeds Sens threshold (becomes green) and the noise level (while not singing or playing) does not (red).

Recognize (Sound source type)

You can select a sound source type that defines your type of instrument or voice. For example:

•	Voice (syllables) – choose this option when you are singing using syllables for each note such as To(recommended), Pa, La, Pe etc.

•	Voice (singing) - choose this option when you are singing lyrics.

•	Guitar (or other instrument) - choose this option when you are playing the same instrument.

From note [??] to [??] (Note recognition range)

Composer can recognize pitches from C3 to B8 just under 6 octaves. You will achieve better results if you set the note recognition range to within that of your instrument or voice.

Playback mode (while recording)

•	Nothing – play nothing

•	Selected tracks - all previously recorded tracks (and turned On in Track List) will be played during recording so you can sing the second part of your music

•	Recorded notes – all recognized notes will be played on your sound system

Some of sound cards use Wave Synthesis for playing MIDI and when Composer is trying to playback recognized notes or previously recorded tracks while recording, it's conflicting with WAVE device. In this case you’ll receive the message that another device is already recording WAVE. To resolve this problem you can set Playback mode - Nothing or select another WAVE device at your sound card configuration.

Play/Add settings – Inst (Instrument)

You can choose Instrument for playing recorded notes.

Play/Add settings – Drum

In Drum mode all notes produce drum beats.

Adjust to scale

It’s very hard to sing perfectly in tune at all times. Moreover, voice (and even instrument!) is sliding over many frequencies during the duration of a single note. When you stop recording Composer automatically finds the nearest musical Scale (max %) for your melody. You can attempt to correct your melody choosing appropriate scale. Chromatic scale doesn’t correct any notes.

Change octave

You can change Octave of recorded notes. For example, if you are whistling you can set lower Octave than recognized.

Play | Stop button

After you have recorded melody you can play it by clicking on Play button.

Add track button

After you have recorded your melody and set appropriate octave, instrument and scale you can add melody as a new track to your composition by clicking on Add track button. This option is available only in registered version.


Main Audio Settings

Before recording any notes with Composer make sure that your sound system is functioning properly.

Microphone connection

Make sure your microphone lead is correctly connected to microphone jack of your sound card. The jack may be labeled with the abbreviation 'MIC' or with a symbol depicting a microphone. Make sure you have a good quality microphone (a 600-ohm, -75dB microphone is fine).

Volume setting

Make sure that the microphone (or other input device if you want) recording input level is set to maximum. To do this: click on Volume Control button and Windows Sound Mixer is opened (standard windows application SNDVOL32.EXE in Windows directory) or double-click on the speaker symbol on the bottom right corner of the screen or click on Start / Programs / Accessories / Multimedia / Volume Control. Go to the options menu/properties and select Recording Control, click OK. You will now have the recording control window. Make sure that the microphone recording volume is set to maximum and MIDI recording level is set to minimum (or disabled). In fact you should always make sure before using Composer that the MIDI recording option is disabled in your mixer and that MIDI playback is enabled.

Test WAVE recording

Run the Windows Sound Recorder application (you can use any alternative audio recording software you may have). To run it do the following: click on Start / Programs / Accessories / Multimedia / Sound Recorder.

Verify that the Sound Recorder utility works by recording and playing back sound. Use the record button to start recording sound at the microphone.  Use the stop button to stop recording.  Use the play button to playback the recorded sound. Make sure that the sound source is of sufficient volume and is close enough to the microphone.

If you cannot get the Sound Recorder to record and playback sound properly, verify all microphone and speaker connections and try again.  Should you find you cannot get your sound system to work properly, you may have one or more defective components.  If the microphone is working, you should be able to scroll through a picture of the sound using the slider control.  If  the line is flat throughout the recorded track you may have a defective microphone or it may be improperly connected.  If you cannot resolve the problem, contact your dealer for assistance.


Improving Recognition results

Sens (Record level and Sens threshold)

During recording at Sens bar you can see record level in decibels (dB). You must adjust Sens threshold (sensitivity) using Sens slider so that maximum record level will be more than sensitivity and mimimum level will be less. The notes will be well recognized only when the level of useful signal (while singing) exceeds Sens threshold (becomes green) and the noise level (while not singing or playing) does not (red).

Microphone position

While recording it is very important to have the microphone properly positioned. Here is a list of what you must keep in mind while recording:

•	sing or whistle with sufficient volume

•	hold the microphone close but not quite touching your mouth

•	don’t hold the microphone in front of your mouth - the air blown onto the microphone will be picked up as noise

•	don’t have excessive background noise

•	don’t set maximum speaker volume (for best results use headphones).

Singing

When singing you will get better results if you avoid singing lyrics since the recognition may interpret the attack of individual syllables of a word as separate notes therefore not producing the desired results. Try singing using syllables for each note such as To (recommended), Pa, Ba, Pe etc. Try also not to sing using a legato style since this will make it more difficult for the recognition to indentify the onset and offset of a note.


Frequently Asked Questions

I can’t open Record window…

If you can’t open Record track window this usually means that Composer has been unable to find the WAVE Input device. To check whether the device is installed, open Control Panel / Multimedia / Audio. There should be accessible even one input device. Also make sure that your sound system is functioning properly (read section Main Audio Settings).

The volume indicator at the Sens bar doesn't show any activity.

Make sure that the microphone recording input level is set to maximum. Please, read section Main Audio Settings.

Why do I get the message “ATTENTION: Your processor is too busy (>???%)”?

The complicated mathematical algorithms of the analysis of digital signals require a great amount of calculations and consequently fast computer. In real time Composer reliably works only on processors Pentium 133 and higher. On weaker machines the incorrect work or dead halt of the program is possible which is removed through pressing Ctrl-Alt-Del keys.

Why do I get the message that another device is already recording Audio?

Some of sound cards use Wave Synthesis for playing MIDI and when Composer is trying to playback recognized notes or previously recorded tracks while recording, it's conflicting with WAVE device. In this case you’ll receive the message that another device is already recording WAVE. To resolve this problem you can set Playback mode - Nothing or select another WAVE device at your sound card configuration.

When I try to recognize music from audio CD I get many accidental notes… What’s wrong?

Let's mark again that Composer recognizes polyphonic music with one instruments or voice. This means you won't get the appropriated results if you try to record more than one instrument playing at the same time. But you can try to detach one instrument from polyphonic music by setting the note recognition range to within that of this instrument.

Why any recorded notes produce cyclic process?

Make sure that the MIDI recording is disabled at your mixer settings.

How to sing the second part of my music?

In Playback mode – Selected Tracks all previously recorded (and turned On in Track List) tracks will be played during recording so you can sing the second part of your music.


System Requirements

•	PC compatible Pentium 133 processor or faster system (for real time conversion)

•	Windows 95/98/NT

•	Sound card (microphone – optional)


How to Register

AKoff Music Composer is freely distributable Shareware. You can download and try it for free.

If you decide to keep it, you have to register and pay the registration fee - US $20. You can order your personal registration key to AKoff Music Composer online via Internet with any major credit card. We accept various types of payment, visit www.akoff.com for details.

As soon as we'll be notified that your order has been processed (usually in one business day for online credit card payments), we'll send you the registration key which will remove all limitations of unregistered version.

If you will not get your registration key within a reasonable amount of time (two business days for online credit card payments), please notify us about that. It may mean, by the way, that the e-mail address in your order form is invalid.

Registered users will receive all future versions and upgrades free, as well as lifetime technical support. You can send all questions to support@akoff.com.

© 1998,1999 AKoff Sound Labs, Inc.