Qtractor is an Audio/MIDI multi-track sequencer application written in C++ with the Qt framework.
FMIT
MIT is a graphical utility for tuning your musical instruments, with error
and volume history and advanced features like microtonal tuning, statistics,
and various views like waveform shape, harmonics ratios and real-time Discrete
Fourier Transform (DFT). All views and advanced features are optional so that
the interface can also be very simple.
NO
Non is the result of one man’s desire to build a complete free-software Digital Audio Workstation on GNU/Linux that really works–on accessible hardware.
samplv1
samplv1 is an old-school all-digital polyphonic sampler synthesizer with stereo fx.
Giada
Giada is an open source, minimalistic and hardcore music production tool. Designed for DJs, live performers and electronic musicians.
OcenAudio
Easy, fast and powerful audio editor