DirectMusic Producer is used to create and edit songs for playback using Microsoft DirectMusic. It was once very popular: article on Microsoft's site here 'How to Use DirectMusic Producer to Create Music for a Video Game' and another guide here (Internet Archive) sample (Archive.today backup)
The most recent 9.0b version from the Microsoft download page (before it was taken down) was a file named "dx90_directmusicproducer.exe" around 30MB in size.
- From this website: File:DMP9.zip
- DirectX 9.0b SDK Extras: DirectMusic Producer (dx90_directmusicproducer.exe) (DMP9.zip) download (Internet Archive) (also Internet Archived via dropbox but dropbox retroactively forbid the timed download URL).
- DirectMusic Producer DirectX 8.1 (DMusProd) (dx81musicproducer.exe) download (Internet Archive)