• You can find a list with audio applications for linux at the page of wikipedia.org: http://en.wikipedia.org/wiki/Linux_audio_software

• A good resource to find linux audio applications for a specific area (notation editors, drummachines etc. etc.) is the application page of linuxaudio.org, section 'Audio Applications': http://apps.linuxaudio.org/

• The Best Programs in Ubuntu Studio, you can find here. It's giving short descriptions of Ardour Digital Audio Workstation, Hydrogen drummachine, Jamin professional audio mastering and more. No debate about opinions, but I can name some more

• JACK is a low-latency audio server, written for GNU/Linux and Apple's OS X. It can connect a number of different applications to an audio device, as well as allowing them to share audio between themselves. Its clients (a Media Player, DAW and/or a drummachine for example) can run in their own processes (ie. as normal applications), or they can run within the JACK server (ie. as a “plugin”).

JACK was designed from the ground up for professional audio work, and its design focuses on two key areas:

1. low latency operation, and
2. synchronous execution of all clients.

• QjackCtl - a gui for JACK (works also on OS X and Windows). QjackCtl Quickstart Guide.

• Patchage is a modular patch bay for audio and MIDI systems based on Jack, Lash, and Alsa audio systems.

• LASH stands for LASH Audio Session Handler. It is a session management system for audio applications on GNU/Linux. It understands the JACK low latency audio API and the ALSA MIDI sequencer interface. The system is comprised of a server program, lashd, an application library, liblash, and a control program - either the command-line lash_control or the GTK lash_panel. The server and clients communicate over TCP sockets. There are three kinds of clients: normal clients (audio applications), user interfaces for the server, and connection patchbays.

With LASH you can save and open music/audio production sessions, so you don't have to load a particular session with specific settings again by hand, you just open the saved session with LASH.

• List of notation editors for Linux check the submenu: music notation.
• Article by Dave Philips about notation editors for Linux (e.g. NtEd, Lilypond, MuseScore, Canorus and more.)

• LilyPond is an automated engraving system. It formats music beautifully and automatically, and has a friendly syntax for its input files. It is Free Software (‘open source’). More information you can find here and at the Lilypond page of wikipedia .
• What's wrong with computer music notation and notation software? Find answers here
• What happens when someone tries LilyPond after using Finale for years? An nice article by Andrew Hawryluk who made that step and compared Finale with Lilypond.
• Here an article by Dave Philips about Lilypond.

• Frescobaldi is a Free Software project to make working with the LilyPond music typesetter within KDE very easy. If you are a LilyPond user and you have KDE, then Frescobaldi is for you (work also nice on Gnome).
• Lilypondtool very usefull in combination with Jedit.
• Using music notation in OpenOffice.org OOolilypond.

Rosegarden,NtEd.
_{(Do's and dont's Rosegarden to Lilypond)}

* NtEd is a new musical score editor for Linux, with a Lilypond export function. It's totally WYSIWYG and very fast. It's pc-keyboard insert function is similar to the 'quick insert function' of Finale. NtEd does have a unique midi import function and much more.

• MuseScore or mscore is a free cross platform WYSIWYG music notation program, licenced under GNU GPL. This program works on Windows and MacOSX too and is comparable with Finale and Sibelius. Here you can find more information.
• MuseScore plays your score with an integrated soundfont engine.
• MuseScore can import MusicXML, Overture files, Band-in-a-Box and Capella files. You can save your score in several graphic formats (PNG, PDF, etc.), but also to MIDI, MusicXML or Ogg, FLAC, Wave. You can also export to Lilypond if you really need futher tweaking.
• Introduction to MuseScore for musicians and music educators.
• MuseScore articles

• Rosegarden is a well-rounded audio and MIDI sequencer, score editor, and general-purpose music composition and editing environment. You can use Rosegarden to make Lilypond files. Rosegarden is an easy-to-learn, attractive application that runs on Linux, ideal for composers, musicians, music students, and small studio or home recording environments. The score editor of Rosegarden is great and much improved in the latest versions.
• Here you can find an review of Rosegarden 1.5 by Dave Philips.

• Ardour is a digital audio workstation. You can use it to record, edit and mix multi-track audio. You can produce your own CDs, mix video soundtracks, or just experiment with new ideas about music and sound.

Ardour capabilities include: multichannel recording, non-destructive editing with unlimited undo/redo, full automation support, a powerful mixer, unlimited tracks/busses/plugins, timecode synchronization, and hardware control from surfaces like the Mackie Control Universal. If you've been looking for a tool similar to ProTools, Nuendo, Pyramix, or Sequoia, you might have found it. Above all, Ardour strives to meet the needs of professional users. This means implementing all the “hard stuff” that other DAWs ( even some leading commercial apps ) handle incorrectly or not at all. Ardour has a completely flexible “anything to anywhere” routing system, and will allow as many physical I/O ports as your system allows. Ardour supports a wide range of audio-for-video features such as video-synced playback and pullup/pulldown sample rates. You will also find powerful features such as “persistent undo”, multi-language support, and destructive track punching modes that aren't available on other platforms.

• Audacity is free, open source software for recording and editing sounds. It is available for Mac OS X, Microsoft Windows, GNU/Linux, and other operating systems.

• Qtractor is an Audio/MIDI multi-track sequencer application written in C++ with the Qt4 framework. Target platform is Linux, where the Jack Audio Connection Kit (JACK) for audio, and the Advanced Linux Sound Architecture (ALSA) for MIDI, are the main infrastructures to evolve as a fairly-featured Linux desktop audio workstation GUI, specially dedicated to the personal home-studio.

• LMMS aims to be a free alternative to popular (but commercial and closed- source) programs like FruityLoops/FL Studio, Cubase and Logic allowing you to produce music with your computer. This includes creation of loops, synthesizing and mixing sounds, arranging samples, having fun with your MIDI-keyboard and much more… Demo.

• Hydrogen is an advanced drum machine for GNU/Linux. It's main goal is to bring professional yet simple and intuitive pattern-based drum programming. Demo.

• Freecycle is a beat slicer running on GNU/Linux platform using the QT toolkit, providing amplitude domain and frequency domain beat matching / zero crossing algorithms. It exports sliced audio chunks and generates a MIDI file which can be used to play the sliced loop, or you can jam with it as soon as you've made slices using a midi keyboard or sequencer. Freecycle also exports AKAI S5000/S6000/Z4/Z8 .AKP files to be used with your favorite sampler, and supports slice drag and drop from the application to the desktop. It can process the audio inline using LADSPA effects, as well as applying envelopes to seperate slices. Article in Linux Journal.

• Smasher is a cross-platform audio loop slicer designed to create sliced loops from WAV, MP3, FLAC or AIFF files in seconds without a sequencer. Effects include filter sweeps, phasing, flanging, delay, and distortion.

• Mixxx is an open source DJ tool designed for both professional and amateur DJs alike.

Mixxx allows DJs to mix music live with a clean, simple interface. Futhermore, Mixxx has a number of key features to help DJs in the mix: Beat estimation, parallel visual displays, and support for various DJ hardware controllers.

• Ultramixer is a DJ mixing software which enables you to mix digital music in various formats such as MP3, WMA, AAC, OGG, WAV or CDs in real time. All you need is a sound card. The DJ's turntables are replaced by two digital SoundPlayers, the “vinyls” are available within seconds through the integrated FileArchive. There are three versions of UltraMixer available: the Free Edition and the Basic Edition for private users and the Professional Edition for high demands and commerical use. All versions are integrated in one program, and can be activated through the appropriate licence keys. This enables the user to switch to a more advanced version without any problems.

• xwax is open-source vinyl emulation software for Linux. It allows DJs and turntablists to playback digital audio files (MP3, Ogg Vorbis, FLAC, AAC and more), controlled using a normal pair of turntables via timecoded vinyls. It's designed for both beat mixing and scratch mixing. Needle drops, pitch changes, scratching, spinbacks and rewinds are all supported, and feel just like the audio is pressed onto the vinyl itself. The focus is on an accurate vinyl feel which is efficient, stable and fast.

• guitarix is a simple mono Rock Guitar amplifier for jack with some effekts like distortion, freeverb, crybaby, echo and ImpulseResponse. It include controlls for bass and treble, in and out gain, feedback and feedforward. guitarix work as stand alone app or as ladspa plugin. Extra GUI functions are the simple useage from jconv (by Fons Adriaensen) for ImpulseResponse and jack_capture (by Kjetil S. Matheussen) for capture.

download guitarix

• Tuxguitar With TuxGuitar, you will be able to compose music using the following features: Tablature editor; Score Viewer; Multitrack display; Autoscroll while playing; Note duration management; Various effects (bend, slide, vibrato, hammer-on/pull-off); Support for triplets (5,6,7,9,10,11,12); Repeat open and close; Time signature management; Tempo management; Imports and exports gp3,gp4 and gp5 files.

• Article by Dave Philips about Rackarrack. 'Rakarrack includes ten effects processing modules, 80 preset patches, a built-in tuner, and a monophonic pitch-to-MIDI converter'. Demo

• AZR-3 [JACK] is a standalone port with JACK support of the free VST plugin AZR-3. It is a tonewheel organ with drawbars, distortion and rotating speakers. The original was written by Rumpelrausch Täips.

• The CALF Organ is a versatile organ/pad synthesizer, capable of producing many types of sounds - tonewheel organs (up to 9 drawbars), solid state organs (9 oscillators with many waveforms to choose from, for each oscillator independently, individual panning, phase shift and detune for each oscillator), strings-like or choir-like pads (thanks to a set of long looped samples generated using padsynth algorithm invented by Nasca Octavian Paul), as well as basses and leads. The sound from some or all oscillators can be processed using 2 independent (but connectable) filter sections, controlled by up to 3 ADSR envelopes. There is also a vibrato/chorus/phaser section to make the sound more vivid.

• AlsaModularSynth. AlsaModularSynth is a realtime modular synthesizer and effect processor. It features:

MIDI controlled modular software synthesis, Realtime effect processing with capture from e.g. “Line In” or “Mic In”, Full control of all synthesis and effect parameters via MIDI, Integrated LADSPA Browser with search capability, JACK Support. Demos Published by German Keyboards magazine.

• Psychosynth Is a Reactable like software synth. 'The Reactable is a collaborative electronic music instrument with a tabletop tangible multi-touch interface. Several simultaneous performers share complete control over the instrument by moving and rotating physical objects on a luminous round table surface. By moving and relating these objects, representing components of a classic modular synthesizer, users can create complex and dynamic sonic topologies, with generators, filters and modulators, in a kind of tangible modular synthesizer or graspable flow-controlled programming language.' What Reactable does with hardware Psychosynth wants to do in software. More information you can find in an article by Dave Philips for Linuxjournal. Demo at blip.tv

• ZynAddSubFX. The famous and loved synth for Linux and Windows. Demo. More Demos.

• Aeolus is a synthesised pipe-organ instrument written by Fons Adriaensen. The default sounds have been skillfully programmed and are very realistic; this means that Aeolus can be very satisfying to play, or to listen with your favourite MIDI files.demo

• AmSynth AmSynth stands for Analogue Modeling SYNTHesizer. It provides virtual analogue synthesis in the style of the classic Moog Minimoog/Roland Junos. It offers an easy-to-use interface and synth engine, while still creating varied sounds. Demo. More information in an article by Dave Philips for linuxjournal.com

• Minicomputer. 'Minicomputer is designed especially for making sounds typically associated with experimental music in the industrial and grindcore styles. It is essentially a monophonic subtractive synthesizer architecture similar to amSynth, but with a considerably expanded design. Minicomputer is fully controllable with MIDI and employs JACK for its realtime audio output'. Article by Dave Philips about Minicomputer. Demo

• Synth of Noise. 'The Synth Of Noise falls squarely into the class of music machines designed for experimental and improvisational sound design. Justin Smith, the synth's creator, has written that the Synth Of Noise was inspired by the works of Iannis Xenakis and Merzbow, composers known for their use of noises and other typically “unmusical” sounds. Indeed, the Synth Of Noise thrives in such sound-worlds'. More information about Synth of Noise in this article by Dave Philips for linuxjournal.com.

• PHASEX is an experimental software synthesizer for use with Linux/ALSA/JACK. The name comes partially from its experimental method of using phase offset modulation, where each oscillator can have its phase offset between right and left channels modulated by an LFO or another oscillator.

Great advantage of PHASEX is that every single knob or slider can be controlled via MIDI.

• JackMaster “Master Console” for the jack-audio-connection-kit.

• Jackmixer is GTK (2.x) JACK audio mixer with look similar to it`s hardware counterparts. It has lot of useful features, apart from being able to mix multiple JACK audio streams.

• Livemix Mix table (base on jack) for live performances. The design will be based on Spirit by Soundcraft live tables.

• Wikipedia about SoundFonts.

• FluidSynth is a real-time software synthesizer based on the SoundFont 2 specifications. FluidSynth can read MIDI events from a MIDI input device and render them to an audio device using SoundFont instruments. SoundFont files are composed of digital audio “samples” and additional instrument parameters. These files can be created or downloaded off the Internet. FluidSynth also has support for controlling effects in real time and can play MIDI files.

• Qsynth Qt GUI Interface for FluidSynth.

• Swami. The Swami Project - Sampled Waveforms And Musical Instruments - is a collection of free software for editing and sharing MIDI instruments and sounds. Swami aims to provide cross platform (Linux, Windows and Mac OSX) instrument editing and sharing software for instrument formats such as SoundFont, DLS and GigaSampler.

• LinuxSampler is a music sampler under active development, aiming to provide a pure software audio sampler with professional grade features, comparable to both hardware and commercial Windows or Mac software samplers and to introduce new features not yet available by any other sampler. Much of LinuxSampler is free software but some, such as the backend, is non-free. LinuxSampler can handle *gig files. More information in this article in Linuxjournal.
• JSampler ”Fantasia”, a frontend to LinuxSampler, modern skin-based distribution of JSampler.

• Specimen is an open source, MIDI controllable audio sampler for Linux.

• Jamin JAMin is the JACK Audio Connection Kit (JACK) Audio Mastering interface. JAMin is an open source application designed to perform professional audio mastering of stereo input streams. It uses LADSPA for digital signal processing (DSP).

• Rosegarden is a well-rounded audio and MIDI sequencer, score editor, and general-purpose music composition and editing environment.

• MusE is a MIDI/Audio sequencer with recording and editing capabilities written by Werner Schweer. MusE aims to be a complete multitrack virtual studio for Linux.

• Qtractor is an Audio/MIDI multi-track sequencer application written in C++ around the Qt4 toolkit. The initial target platform will be Linux, where the Jack Audio Connection Kit (JACK) for audio, and the Advanced Linux Sound Architecture (ALSA) for MIDI, are the main infrastructures to evolve as a fairly-featured Linux Desktop Audio Workstation GUI, specially dedicated to the personal home-studio.

• Seq24 is a minimal loop based midi sequencer. It was created to provide a very simple interface for editing and playing midi 'loops'. After searching for a software based sequencer that would provide the functionality needed for a live performance, such as the Akai MPC line, the Kawai Q80 sequencer, or the popular Alesis MMT-8, I found nothing similar in the software realm. I set out to create a very minimal sequencer that excludes the bloated features of the large software sequencers, and includes a small subset of features that I have found usable in performing. Article about Seq24 in Linuxjournal.

• Freewheeling is a new way to be In The Muse-ical Moment. It's a live looping instrument that returns us to the joy of making music spontaneously. allows us to build repetitive grooves by sampling and directing loops from within spirited improvisation.

• Article about Freewheeling at Linuxjournal.com
• Demo video, Drum demo video

• SooperLooper is a live looping sampler capable of immediate loop recording, overdubbing, multiplying, reversing and more. It allows for multiple simultaneous multi-channel loops limited only by your computer's available memory. The feature-set and operation was inspired by the impressive Gibson Echoplex Digital Pro (EDP). When used with a low-latency audio configuration SooperLooper is capable of truly realtime live performance looping.

• MMA—”Musical MIDI Accompaniment” is an accompaniment generator. It creates midi tracks for a soloist to perform over from a user supplied file containing chords and MMA directives. MMA is very versatile and generates excellent tracks. It comes with an extensive user-extendable library with a variety of patterns for various popular rhythms, detailed user manuals, and several demo songs. MMA is a command line driven program. It creates MIDI files which are then played by a sequencer or MIDI file play program.

• Impro-Visor (short for “Improvisation Advisor”) is a music notation program designed to help jazz musicians compose and hear solos similar to ones that might be improvised. The objective is to improve understanding of solo construction and tune chord changes. There are other, secondary, things it can do, such as improvise on its own. It has also been used for transcription. Because rhythm-section (e.g. piano, bass, drums) accompaniment is automatically generated from chords, Impro-Visor can be used as a play-along device. Now having a wider array of accompaniment styles, its use is not limited to jazz. Distributed with Impro-Visor is “The Imaginary Book”, a chords-only fakebook with chord progressions to about 2500 tunes.

• Solfege Solfege is free music education software.

Use it to train your rhythm, interval, scale and chord skills. Solfege - Smarten your ears!

• Klick is an advanced command-line based metronome for JACK. It allows you to define complex tempo maps for entire songs or performances. Features:

Support for tempo maps, including arbitrary meters, tempo changes, accelerando/ritardando and more. Three built-in sounds (borrowed from Ardour, GTick and FreePats), plus ability to load your own samples. JACK transport sync support (master/slave). No GUI ;)

• Fmit Free Music Instrument Tuner.

• Play it slowly is a small tool to play audio files at a different speed or pitch. It does also allow you to loop over a certain part of a file. It's intended to help you learn or transcribe songs.

• Pd(aka Pure Data) is a real-time graphical programming environment for audio, video, and graphical processing. It is the third major branch of the family of patcher programming languages known as Max (Max/FTS, ISPW Max, Max/MSP, jMax, etc.) originally developed by Miller Puckette and company at IRCAM. The core of Pd is written and maintained by Miller Puckette and includes the work of many developers, making the whole package very much a community effort. Pd was created to explore ideas of how to further refine the Max paradigm with the core ideas of allowing data to be treated in a more open-ended way and opening it up to applications outside of audio and MIDI, such as graphics and video.

• Csound is a sound design, music synthesis and signal processing system, providing facilities for composition and performance over a wide range of platforms. It is not restricted to any style of music, having been used for many years in the creation of classical, pop, techno, ambient, experimental, and (of course) computer music, as well as music for film and television.

• ChucK is a new (and developing) audio programming language for real-time synthesis, composition, performance, and now, analysis - fully supported on MacOS X, Windows, and Linux. ChucK presents a new time-based, concurrent programming model that's highly precise and expressive (we call this strongly-timed), as well as dynamic control rates, and the ability to add and modify code on-the-fly. In addition, ChucK supports MIDI, OSC, HID device, and multi-channel audio. It's fun and easy to learn, and offers composers, researchers, and performers a powerful programming tool for building and experimenting with complex audio synthesis/analysis programs, and real-time interactive control.

• SuperCollider is an environment and programming language for real time audio synthesis and algorithmic composition. It provides an interpreted object-oriented language which functions as a network client to a state of the art, realtime sound synthesis server. SuperCollider was written by James McCartney over a period of many years, and is now an open source project maintained and developed by various people. It is used by musicians, scientists, and artists working with sound.

• JSynthLib is a Java-based universal editor/librarian for MIDI hardware. Currently supported synths are listed on this list. (+Novation XioSynth, not listed there yet, but already supported in the latest version)

• MilkyTracker is an open source, multi-platform music application for creating .MOD and .XM module files. It attempts to recreate the module replay and user experience of the popular DOS program Fasttracker II, with special playback modes available for improved Amiga ProTracker 2/3 compatibility.