The Advanced Linux Sound Architecture is composed of several parts. The first is a fully modularized sound driver which supports module autoloading, devfs, isapnp autoconfiguration, and gives complete access to analog audio, digital audio, control, mixer, synthesizer, DSP, MIDI, and timer components of audio hardware. It also includes a fully-featured kernel-level sequencer, a full compatibility layer for OSS/Free applications, an object-oriented C library which covers and enhances the ALSA kernel driver functionality for applications (client/server, plugins, PCM sharing/multiplexing, PCM metering, etc.), an interactive configuration program for the driver, and some simple utilities for basic management.
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.
jMusic provides a library of classes for generating and manipulating music, and is a solid framework for computer assisted composition in Java. jMusic supports composers by providing a music data structure based upon note/sound events, and methods for working with that musical data. jMusic can read and write MIDI files, audio files, and its own .jm files. jMusic is designed to be extendible, encouraging you to build upon the functionality of jMusic by programming in Java to create your own music composition tools.
libmidixx is a C++ library to manipulate MIDI sequences. It is intended for a multimedia application that handles playback, recording, and editing of MIDI sequences, though the current version just implements playback only. libmidixx supports OSS, ALSA, and serial (tty) MIDI ports, and also comes with a user-space sequencer implementation, which does a fair job on a lightly-loaded machine.
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.
MidiMountain is a sequencer to edit standard MIDI files. Its easy-to-use interface should help beginners to edit and create MIDI songs (sequences), and it is designed to edit every definition known to standard MIDI files and the MIDI transfer protocol, from easy piano roll editing to changing binary system exclusive messages.
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.