Thesia is a Multi-track Spectrogram / Waveform viewer This project is in beta.

Recorder is a simple, cross-platform audio recording application.
gPodder is a simple, open source podcast client.
In development since 2005 with a proven, mature codebase.

gpodder.github.io
github.com/gpodder/gpodder
www.wikidata.org/wiki/Q3093354
gpodder.net is a libre web service that allows you to manage your podcast subscriptions and discover new content. If you use multiple devices, you can synchronize subscriptions and your listening progress.
It works best with the gPodder application, but you can also use it with Amarok, other supported clients or as standalone web application without any client app.
I’ve written a program that makes it easier to listen to classical music, or other music that has a wide range of volumes, at low volumes or in high noise conditions (such as in your car) so that you can still hear the soft parts. I’ve also written a plugin version, designed to be used with the free audio editor Audacity. You can read about the background and rationale of the plugin here.
Tiny Qt Music Player to keep your favorite songs at hand.
apps.kde.org/vvave
github.com/KDE/vvave
flathub.org/en/apps/org.kde.vvave
GSonic Reference is a high-quality speaker and room correction tool that generates precision FIR correction filters from in-room measurements. It combines spatial measurement averaging with advanced filter generation to deliver studio-grade correction for any stereo listening environment.
github.com/ObsessiveCompulsiveAudiophile/GSonic
hydrogenaudio.org/index.php/topic,129351.0
Pear Desktop is an Electron-based desktop client for YouTube Music designed for Windows, Linux and macOS. The project keeps the standard YouTube Music interface while adding desktop integration, plugins, themes and additional playback features.
The application is open source and distributed under the MIT license.

Pear Desktop loads the standard YouTube Music web interface inside a desktop application window and extends it through plugins and Electron desktop integration. It is not a standalone music service and still requires a YouTube Music or Google account for normal use.
Because Pear Desktop uses Electron, memory and CPU usage are generally higher than lightweight native audio players such as foobar2000 or AIMP. The project is intended primarily as a feature-enhanced desktop frontend for streaming music from YouTube Music rather than as a traditional local-library music player.
A set of utilities for working with Byzantine sheet music.
PsalticTools includes:
• a set of utilities (plugins) for typing of Byzantine notes in parallel double notation (Byzantine and Western), based on MuseScore free music editor;
• the PsalticHelper program for searching for formulas of Byzantine music in music books.
• the UniPsaltica2 font with the characters of the musical Byzantine notation in Unicode.
sourceforge.net/projects/psaltichelper
en.wikipedia.org/wiki/Byzantine_music
sourceforge.net/projects/byzorgan/
A cross-platform music player based on PyQt5, supports Win32, Linux and macOS.