Jajuk - Jajuk is software that organizes and plays music using Java.
Ring4 Meeting - Dead simple video conferencing - free, in browser
GNOME Music - Music is the new GNOME music playing application.
Stork.ai - AI-Based Collaboration for Hybrid Teams. Rich media messaging, advanced video and voice conferencing, auto-transcribing and screen sharing. Serendipitous meetings at the water-cooler with your human and AI teammates.
Sayonara Player - Sayonara is a simple but nice audio player and holds a lot of features like a library, id3 tag...
openmeet - Account free video conferencing with a rooms component that lets you use VC within a physical meeting room. The server can also be hosted in your own cloud for extra privacy/security.