MusE is a multitrack virtual studio for Linux. It supports real-time editing of both MIDI and audio in an integrated environment. It has support for LADSPA and DSSI plugins (with Win VST support), JACK, and ALSA-MIDI output and input as well as internal softsynths. Numerous MIDI editors are available, including a piano roll, score editor, and drum editor. There is full automation for both MIDI and audio.
Beast is a powerful music composition and modular synthesis application. It offers multiple input methods like multitrack, piano roll, and pattern editing and supports skins. On the technical side, it has a wide range of abilities like sequencing, unlimited undo/redo history, real-time synthesis with multiprocessor support, full duplex 32-bit audio rendering, precise timing down to sample granularity, on demand loading of partial wave files, on the fly decoding of various sample formats, aliasing free oscillators, and full Scheme scripting support.
Melys is a MIDI sequencer application for ALSA. It records, plays back, and saves to a MIDI file or to an XML-based format. There is a track view where you can arrange parts using drag-and-drop and a piano-roll view where the same can be done with notes. There is also a graphical tempo view where the tempo of the song can be changed. Multiple files can be open at once, and notes can be dragged between them. It is written in C and uses the GNOME/Gtk+ widget sets.
Smurf is a GTK-based SoundFont editor. SoundFont files are a collection of audio samples and other data that describe instruments for the purpose of composing music. SoundFont files do not describe the music itself, but rather the sounds of the instruments. These instruments can be composed of any digitally recordable or generated sound. This format provides a portable and flexible sound synthesis environment that can be supported in hardware or software. Note that Swami is the successor to Smurf and is an entire object-oriented rewrite of it.
Sfront compiles MPEG 4 Structured Audio (MP4-SA) programs into efficient C programs that generate audio when executed. MP4-SA is a standard for normative algorithmic sound, which combines an audio signal processing language (SAOL) with score languages (MIDI and SASL). Under Mac OS X and Linux, sfront supports real-time, low-latency audio input/output and MIDI input. Under Mac OS X, sfront supports the creation of AudioUnit plug-ins. The documentation includes a book about SAOL programming.
Ecasound is a software package designed for multitrack audio processing. It can be used for simple tasks like audio playback, recording, and format conversions, as well as for multitrack effect processing, mixing, recording and signal recycling. It supports a wide range of audio inputs, outputs, and effect algorithms. Effects and audio objects can be combined in various ways, and their parameters can be controlled by operator objects like oscillators and MIDI-CCs. A versatile console-mode user interface is included in the package.
KeyKit is a multi-tasking interpreted programming language (inspired by awk) designed exclusively for realtime and algorithmic MIDI manipulation. KeyKit's GUI provides several dozen tools for algorithmic music experimentation, including a multi-track sequencer and drum pattern editor. The GUI and all tools are completely written in the KeyKit language itself. This allows users to add new tools and operations to the existing tools, even while the system is running. Complete C source code and precompiled executables for Windows and Linux are provided.
Paloma is a program to manage an SQL database of digital music files, and facilitate their retrieval and playback in interesting ways. It works with music files of any form -- MP3, Ogg Vorbis, MIDI... whatever you've got a player for. Paloma makes it easy to rip your entire CD collection and store it on your hard disk (or a collection of CD-Rs) for instant random access; playlists can then be generated using arbitrary SQL commands.
Mup produces very high quality PostScript printed music or a MIDI file from a text input file. It can handle almost any kind of music, instrumental or vocal, including tablature, shaped notes, guitar grids, alternate tunings, user-defined symbols, and much more. Mup has been under active development since 1992.