jack-tuner is a musical instrument tuner that uses the JACK audio connection kit. It is a command line program, and it accepts many commands. The important ones are the tone and volume commands, which can produce any audible tone from 20hz to 20khz at a volume from 0 (silence) to 1 (loudest). It can also produce notes (for example, "tone D#" produces the note D#) over several octaves (for example, "tone C octave -1" produces the note C an octave below middle-C). It can also transpose notes (for example, "tone C > 5" produces G). There are commands to do microtonal tuning too. With multiple jack-tuner instances, you can tune chords. jack-tuner does not measure the note that an instrument is playing; instead you play the desired note with jack-tuner and tune your instrument by ear.
AlsaModularSynth is a realtime modular synthesizer and effect processor. It features MIDI controlled modular software synthesis, realtime effect processing with input capture, full control of all synthesis and effect parameters via MIDI, an integrated LADSPA browser with search capability, and JACK support.
QJackRcd is a simple Qt application that records JACK server outputs. It was designed to record audio from tape, with an automatic split/pause feature. It aims to provide for simple stereo recording needs with a minimum of configuration. It natively manages silence by threshold and activation time. Silence events can be used to pause the recording or to split files. It can optionally post-process each file after recording is complete.
LinuxBand is a GUI front-end for MMA (Musical MIDI Accompaniment). Type in the chords, choose the groove, and LinuxBand will play a musical accompaniment for you. It’s an open source alternative to Band-in-a-Box featuring: an easy to use graphical interface, an open and well-documented data format, and output to JACK MIDI to facilitate co-operation with other audio applications.
ng-jackspa is a set of simple user interface programs that host a LADSPA plugin, providing JACK ports for its audio inputs and outputs, and dynamic setting of its control inputs through the user interface. Additionally, the plugin controls can be exported to or controlled by control voltages on standard JACK audio ports. The following interfaces are available: an ncurses visual (full screen) interface for the terminal; a GTK+ graphical interface; a Qt 4 graphical interface; and a command line interface for the terminal.
din is a software musical instrument and audio synthesizer. Bezier curves are used to draw and sculpt waveforms, create gating and modulation (FM and AM) patterns, and create delay feedback and volume patterns. You can also create an unlimited number of drones and sculpt their waveforms. It uses JACK to output audio, and supports MIDI, OSC and IRC bot for input. din can be extended and customized with Tcl scripts.