Tenacity is an easy-to-use, cross-platform multi-track audio editor / recorder for Windows, macOS, Linux and other operating systems and is developed by a group of volunteers as open-source software.

Muine is an innovative music player, featuring a simple, intuitive interface. It is designed to allow users to easily construct a playlist from albums and/or single songs. Its goal is to be simply a music player, not to become a robust music management application. This doesn’t mean Muine has no features! Some feature highlights:
Muine is targeted at the GNOME desktop and uses GTK+ for the interface. Most of the code is written in C#, with some additions/bindings/glue in plain C. Muine was originally written by Jorn Baayen, but now maintained mostly by others.
github.com/mickeyr/Muine
gitlab.gnome.org/Archive/muine
en.wikipedia.org/wiki/Muine
manpages.org/muine
This is a component for the foobar2000 audio player, which provides a skinnable overlay UI.

theqwertiest.github.io/dotnet_title_bar
hydrogenaud.io/index.php?topic=121673
The Daphile is the heart of a digital music system. Its primary focus is in storage and playback of your digital music library. It enables the best possible audio quality and future-proof flexibility by providing plug&play support for USB connected digital-to-analog converters (DAC). You can easily setup a multi-zone system just by connecting another USB DAC for each zone.
Daphile is based on the open source Squeezebox Server, Squeezelite and Linux.
Since Daphile is used and configured completely via the web interface the user is not required to have any Linux skills.

DSF_FillMute is a program that replaces a series of trailing zeros created by the standard of DSF files with a silent signal (0x69,1001 0110b). It is effective for devices that generate noise by playing a series of trailing zeros. There is no change in the actual sound or ID3 tag because no processing is added except at the end.
PCM-DSD Converter is a program that converts a PCM WAV format sound source to DSD DSDIFF format. You can convert from PCM 16bit ~ 64bit Float / 44.1 ~ 768kHz to DSD16-DSD2048.
Adds and fixes music metadata and adds album art.
The PC based Soundcard Oscilloscope receives its data from the Soundcard with 44.1kHz and 16 Bit resolution. The data source can be selected in the Windows mixer (Microphone, Line-In or Wave). The frequency range depends on the sound card, but 20-20000Hz should be possible with all modern cards. The low frequency end is limited by the AC coupling of the line-in signal. Be aware, that most microphone inputs are only mono.
The oscilloscope contains in addition a signal generator for 2 channels for sine, square, triangular, sawtooth wave forms and different noise spectra in the frequency range from 0 to 20kHz. The signal can be defined by a mathematical formula as well. The signals are available at the speaker output of the sound card. These can be fed back to the oscillocope in order to generate Lissajous figures in the x-y mode.

VintageRadio is a GUI front-end for the fm command-line application included with fmtools <http://benpfaff.org/fmtools>. It is written in [incr Tcl/Tk], an object-oriented extension package for Tcl/Tk. VintageRadio is not part of fmtools.

TAL-NoiseMaker is a virtual analog synthesizer with great sound and low CPU usage.

Charlatan is a polyphonic, subtractive virtual analog (VA) synthesizer VSTi plugin with focus on sound quality and easy usability. It comes with a flexible, yet not overwhelming feature set which encourages artists to start tweaking instead of just relying on presets. In spite of it’s simplicity, Charlatan’s architecture is flexible enough to create both classic sounds and rather experimental noises. While making no compromise about sound quality, the sound engine has been highly optimized for efficient CPU usage making Charlatan well suited as a “bread and butter” synth even in projects with a large number of plugin instances. Best of all, it’s freeware! Enjoy!

Transform an album image into a video with songs tracks.
Select your favorite artist’s albums or your own picture with songs or sounds effects and transform it into a video with audio tracks that you can upload to YouTube.