The Pure Data (short Pd) project on SourceForge unifies the extensions (or externals) written for the Pure Data Graphical Computer Music System written by Miller Puckette with contributions from many others.
TiMidity++ is an open source MIDI to WAVE converter and player.
A real-time SoundFont software synthesizer
A real-time software synthesizer based on the SoundFont 2 specifications. It can be used for live audio synthesis of MIDI events or for rendering MIDI files to disk, using SoundFont instruments. It can also be embedded in other applications. This is not a application with a graphical user interface, however there are several GUI applications which utilize FluidSynth.
Bristol is synth emulation package for a diverse range of vintage synthesisers, electric pianos and organs. The application consists of a multithreaded audio synthesizer and a user interface called brighton.
PortMedia offers free, cross-platform, open-source I/O libraries for digital media including MIDI, video, and audio (see www.portaudio.com). Most work is in C to facilitate interoperabilty with many languages and systems.
patch editor for the E-MU Proteus 2000 synthesizer family
A cross-platform patch editor for the E-MU Proteus 2000 sample-based synthesizer family. prodatum is free software.
Firmware loaders for M-Audio/Midiman USB MIDI and Audio devices
Perform dynamic tunings for realtime music.
Mutabor is a Program that allows performing and composing microtonal music using a normal MIDI keybord. But it's powerful description language is intended to allow permanent retunings and tuning logics in to describ, what's actually goes on.
Jack-smf-utils is a set of two utilities - jack-smf-player and jack-smf-recorder - whose purpose is to play and record MIDI streams from/to Standard MIDI Files (i.e. the files with .mid extension) using JACK MIDI. It uses libsmf as a backend.
A SoundFont editor and other software for editing, managing and sharing sample based MIDI instrument files for computer music composition. Support for other formats is planned.
DSSI is an audio plugin API for soft synths and effects.
DSSI is an audio plugin API for software instruments (soft synths) and effects. It is based on the LADSPA plugin API, the ALSA sequencer event types, and OSC (Open Sound Control) communications with custom GUIs.
Music auto-arranger follows your chord changes live and plays along
BackupBand is a music auto-arranger. It has a virtual drummer, bassist, and rhythm guitarist. These 3 "musicians" follow your chord changes live (as you play some MIDI instrument, such as a keyboard) and they play along with you in perfect time. It's like having a live rhythm section backing you up. The rhythm section knows how to play in 60 different styles such as Rock, Disco, HipHop, Heavy Metal, Reggae, Swing, various latin styles, etc. You can also create your own styles for them to play. The bassist plays a rickenbacker, fender precision, synth, and double (acoustic) bass. The guitarist plays a les paul, steel string, and nylon string. The drummer plays 6 kits. You can also create your own multi-sampled guitars, basses, and kits for them to play.
ABC is a text-based music notation language. This project aims to promote the ABC music notation language by providing cross-platform, open-source tools for manipulating, displaying and playing (via MIDI) ABC files.
jack-keyboard is a virtual MIDI keyboard - a program that allows you to send JACK MIDI events (play ;-) using your PC keyboard. It's BSD-licensed. User interface is GTK-based.
a 16-bit midi player for DOS
DOSMid is a real mode (16-bit) midi player for DOS. DOSMid supports a variety of MIDI synthesizers, and has very low hardware requirements.
LibSMF is a BSD-licensed C library for handling SMF ("*.mid") files. It transparently handles conversions between time and pulses, tempo map handling etc. The only dependencies are C compiler and glib. Full API documentation and examples are included. Note that the development has moved to https://github.com/nilsgey/libsmf.
eChanter is an Open Source electronic bagpipe project, based on the Arduino platform, using capacitive touch sensors, with polyphonic wavetable synthesis PCM audio at 8KHz. See Files for the development version, eChanter v3.0.
GMorgan_0.79 updated November 21, 2016
Gmorgan is a midi processor. It can be voiced using Linux synths, midi connected equipment, or a soundcard. It is best to use a velocity sensing midi keyboard so that the first 4 voices can be mixed or layered. Demo at Youtube: http://youtu.be/3uIRq6M1tCs For GNU/Linux users, the latest file is .79. GMorgan .79 runs well on Ubuntu and most Linux/GNU distributions. Although it is included in the tarball, you can download .75 pdf documentation from the files section here. This revision incorporates a new drum pattern panel based on the FLTK spreadsheet example. There is also some miscellaneous cleanup. If you have tried it before, be sure to go to Settings->global, renew the file paths to the current gmorgan directory, and save them. The sound file has been slightly reformated, so results could be unpredictable if you don't do this. Try the play along at http://www.seconnecticut.com/GmorganPlayalong.htm
Tritonus is an independent implementation of the Java Sound API (http://www.javasoft.com/products/java-media/sound/index.html).
record MIDI files from the PC keyboard
Record a melody as a MIDI file, right from the computer keyboard with no special hardware required. Current work on the project is aimed at music analysis. Rhythm and harmony have completed subroutines. A future version of the program will analyze MIDI files, rate their musical value, and recombine them to produce new tunes.
Curses Jack connection manager
Curses Jack connection manager, based on naconnect by Nedko Arnaudov
Play midi files via external midi devices or soft synth.
Playmidi is a curses and SDL-based MIDI file player for Linux and MacOS (windows support planned) It supports software rendering of midi files via SDL audio and can also output midi events to external midi devices (in time with SDL audio soft synth) via both alsa sequencer api (linux) and coremidi api (osx). Soft synth rendering supports sf2 files (soundfont 2.0) but does not require any sf2 files to be installed for sound. Fallback output is available via sine/saw/triangle/square wave synthesis. Math-based synthesis is planned to evolve over time to support most of the features found in a minimoog voyager, and wavetable based sf2 support is expected to evolve to properly emulate all the features of a roland sc88 (but not there yet). Additionally there are issues with some sf2 files, but currently most development in the git tree has happened with one you can find via google search called Scc1t2.sf2. It provides a good starting point for those without external midi hardware
Package to use RockBand 3 Pro Drumkit and Guitar Hero drumkit via midi
FOR LATEST VERSION GO TO https://github.com/rbdrum2midi/rbdrum2midi This userland program uses libusb to gain access to the velocity sensitive data in the rockband 3 wireless usb prodrum controller (with cymbals) and Guitar Hero drumkit and use it as an ALSA MIDI controller. It has a low latency setup so that it can give a fairly good drumming experience.
A viewer for a new kind of music notation
The MIDI File Printer prints a new easy-to-read music notation. It expects standard MIDI files as input, displays them in a configurable way on the screen and prints them out.
Raw MIDI application set
Spiano is a set of MIDI applications for LInux: spiano (virtual keyboard for X), ssynth (piano synth for tuning practise) and splaymid (.mid player).