Midi Sheet Music is a free program that plays MIDI music files while highlighting both the piano keys and sheet music notes. Works on Windows, Mac OS X, Linux Ubuntu, iPhone / iPad and Android.

wtext is a program that will accept ASCII text as input and generate International Morse Code as output. The output formats can be:
DR14 T.meter is a free and open source command line tool for computing the Dynamic Range of your music according to the procedure used in the off-line meter released by the Pleasurize Music Foundation.
This tool is a very useful measure of how loud your music is, and for understanding that a good quality album always has a wide dynamic range, and it’s also useful for understanding the effects of the so called ‘loudness war’.
Dr14 t.meter is released under the terms of the GNU GPLv3 license and is intended for the Linux users who can not use the Windows application released by the Pleasurize Music Foundation, or the plugin for Foobar2000.
I’ve largely tested this application and it has always returned results identical to those of the official off-line meter.
Featured MIDI File Player for Linux, Windows, and macOS written in C++, and using Qt5 and Drumstick2.




dmidiplayer.sourceforge.io
sourceforge.net/projects/dmidiplayer
sourceforge.net/projects/drumstick
TAPClean is a Commodore tape preservation / restoration tool. It will check, repair, and remaster Commodore 64 and VIC 20 TAP or DC2N DMP files (tape images).

Application which detects musical notes from the microphone. It allows listening to the microphone and play the detected notes to output (in MIDI). Multi-language support.
Subsonic is a web-based media streamer, providing ubiquitous access to your music and video collection. More than 20 apps are available for Android, iPhone, Windows Phone, BlackBerry, Roku, Chumby, Sonos etc. Supports virtually all media formats, converting files on the fly. Also includes a Podcast receiver and jukebox feature allowing you to control what’s playing on your computer from your mobile phone.
www.subsonic.org
sourceforge.net/projects/subsonic
github.com/hypfvieh/foo_subsonic
github.com/VD39/subsonic-player
netjukebox is a web-based media jukebox for MPD, VideoLAN and Winamp/httpQ. netjukebox is open source under the GNU GPL license.
Stand alone:
Client and server on one computer. So you can play your favorite music and video from your local hard disk.
Client / Server:
Play music and video from any computer in your network. A working network share is required.
Remote:
Remotely control MPD, VideoLAN or Winamp from any computer.
Stream:
Native HTML5 audio streaming support. Automatic M3U/HLS fallback for unsupported clients.
More:
Download the original file or transcode to another format or bitrate. Generate PDF cd-covers on the fly.
Libretime is an open source radio automation and broadcasting solution helping communities get on-air with ease. LibreTime makes it easy to run your own online or terrestrial radio station. It is a community managed fork of the AirTime project.
Sndio is a small audio and MIDI framework part of the OpenBSD project and ported to FreeBSD, Linux and NetBSD. It provides a lightweight audio & MIDI server and a fully documented user-space API to access either the server or the hardware directly in a uniform way. Sndio is designed to work for desktop applications, but pays special attention to synchronization mechanisms and reliability required by music applications. Reliability through simplicity is part of the project goals.
sndio.org