Amberol
Amberol is a simple music player. Free and open source program
Moosync
Moosync is a simple music player whose main purpose is to provide a clean and simple interface. Free and open source program
Relaxator
Relaxator is a free and open source program for relaxing to the soothing sounds of nature
HBud
HBud is a free and open source simple music/video player and karaoke application
Rhyme
Rhyme is a free and open source, multiplatform, simple and convenient music player
GNOME Music
GNOME Music is a free and open source simple application for playing music
Vvave
Vvave is a free and open source program for playing your music collection for KDE Linux
Glide
Glide is a free and open source, simple and minimalistic media player
Audacious
Audacious is a free and open source, multi-platform, simple, lightweight and advanced music player
DeaDBeeF
DeaDBeeF is a free and open source, multiple-platform modern, simple and minimalist modular audio player