The Geiss screensaver and Winamp music visualization plug-in.

WhatChord is an interactive chord identification, key detection, and harmony exploration app. Identify voicings from live Bluetooth or USB MIDI input or manual note entry, follow the key as you play, then explore chords, scales, keyboard patterns, and harmonic context. It is optimized for speed, accuracy, and musician-expected naming, favoring stable, conventional interpretations over simple note-matching.

whatchord.earthmanmuons.com
github.com/EarthmanMuons/whatchord
Tonbandfetzen is a collection of command-line tools that allow you to compose music based on audio fragments generated from plain text input. It contains:
tz mel– generate sound fragments from plain texttz guitar– read guitar tablaturetz stick– concatenate audio datatz stack– superimpose audio datatz stretch– rescale audio datatz repeat– loop audio datatz trim– strip leading and trailing silencetz mono– unzip audio channelstz harmonics– show spectra of wave samplestz inspect– show information on audio filetz riff2aiff– convert .wav(e) into .aif(f) filestz aiff2riff– convert .aif(f) into .wav(e) filestz tag– add ID3v2 metadata to .wav(e) filestz play– generate and play sound fragments
iamf-toolsimplements tools to help users process and work with the IAMF format. These tools can be used as a complement to thelibiamfreference decoder and other tools such as ffmpeg and MP4Box.
github.com/AOMediaCodec/iamf-tools
References:
aomediacodec.github.io/iamf
en.wikipedia.org/wiki/Alliance_for_Open_Media
Resources:
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
KMix is a sound channel mixer and volume control.

apps.kde.org/kmix
github.com/kde/kmix
invent.kde.org/multimedia/kmix
docs.kde.org/trunk_kf6/en/kmix
userbase.kde.org/KMix
AudioTube can search YouTube Music, list albums and artists, play automatically generated playlists, albums and allows to put your own playlist together. It is adapted to mobile phones and desktop computers.

apps.kde.org/audiotube
github.com/KDE/audiotube
invent.kde.org/multimedia/audiotube
Bitfake was originally created to detect fake
.FLACfiles through spectral analysis. It has since grown into a multipurpose CLI tool for handling music more easily and efficiently.One common problem was that getting a track’s metadata required long
ffprobecommands with messy output. Converting music withffmpegwas also repetitive. The command itself is easy to remember, but writing scripts to convert entire directories felt inefficient and slow. This project now performs metadata and conversion tasks directly through linked libraries (TagLib/libsndfile/libav*).
.FLAC files (higher sample rates may be misrepresented, so be careful).wav, .flac, .ogg, .mp3, .aac, .opus)github.com/Ray17x/bitfake2
gpo.zugaina.org/app-misc/bitfake2
repology.org/maintainer/ray%40atl.tools/feed-for-repo/gentoo_ovl_guru
Gnomoradio is a program that can find, fetch, share, and play music that is freely available for file sharing. Gnomoradio is free software, licensed under the terms of the GNU General Public License, which permits modifications and distribution of the source code to the program. It runs on GNU/Linux and other UNIX-compatible systems, but it is no longer actively developed or maintained.

GLava is a general-purpose, highly configurable OpenGL audio spectrum visualizer for X11.
github.com/jarcode-foss/glava
microenc is a small Bash shell script for Linux/BSD for encoding directories with audio files to other formats using FFmpeg as encoder.
Features:
sourceforge.net/projects/microenc
- Encodes to MP3, AAC, Vorbis, Opus, AC-3, E-AC-3, DTS, FLAC, ALAC, WavPack, AIFF and WAV audio
- Auto-copying of metadata and, for MP3/AAC/FLAC/ALAC/AIFF, cover art
- Optional high-quality audio resampling
- Requires only ffmpeg and ffprobe