2000年就有类似的软件了，可以将钢琴，提琴，笛子等（最好是独奏）的音频文件转化成MIDI
名字叫Composer，曾今作为扒带的辅助工具
以下是readme:
AKoff Music Composer version 2.0
Copyright (C) 1998-2000 AKoff Sound Labs.
DESCRIPTION:
AKoff Music Composer is music recognition software which
performs Wave to Midi conversion. Composer recognizes
polyphonic music from microphone (other Wave input or file)
and converts it into Midi sequences.
You can sing, whistle or play guitar, piano, flute and so on
with your microphone, Composer will automatically recognize
and score your music and create standard Midi sequences.
Neither a Midi keyboard nor any musical experience are required
to compose music.
SYSTEM REQUIREMENTS:
1. PC compatible Pentium 150 processor or faster system
2. Windows 95 or higher
3. Sound card (microphone - optional)
INSTALLATION:
To install our software simply unzip archive in any appropriate
folder and run EXE-file. Our software doesn't place any DLLs or
other libraries to your system folder. To uninstall software
simply delete all files included in distributive.
REGISTRATION:
The unregistered version of AKoff Music Composer allows you to
evaluate the program features before registering it. This version
is fully functional with the following exception: you cannot save
MIDI file. If you decide to continue using Composer after the 30-day
evaluation period, you must register it.
The registration fee is US $29.
DISTRIBUTION:
The unregistered software may be freely distributed provided the
distribution package is not modified. No person or company may
charge a fee for the distribution of Composer without written
permission from the copyright holder.
CONTACTS:
E-mail:
contacts@akoff.com
Website:
www.akoff.com
POSTAL ADDRESS:
AKoff Sound Labs
P.O. Box 2
Moscow 109548
Russia