puddletag is a tag editor for Linux loosely based on mp3tag. It uses a table layout so that all the tags you want to edit by hand are visible and easily editable. puddletag excels at automating repetitive tasks like extracting tag information from filenames, tagging files from a text file or the clipboard, renaming or moving files and folders based on tags by using patterns, and manipulating tags using actions and regular expressions. Supported formats include id3v1, id3v2 (.mp3), AAC (.m4a), VorbisComments (.ogg, .flac), and APEv2 (.ape). Much of mp3tag's functionality has been replicated with added enhancements and tweaks.
CLAM chordata analyses the chords in a song and allows you to navigate along the song while watching several views to get insight of chords and other tonal features. Its simple and handy interface is designed for players with an instrument at hand. This application is part of the CLAM framework.
Quasar Media Player is a light-weight, fast, and convenient media player for mobile systems. It offers many of the features found in modern desktop media players, like fast library overview and filtering along with the ability to handle large libraries very well. It has several unique features that give it unprecedented flexibility on a mobile device, like a zoomable interface for better readability even from a distance, or auto-generated playlists from a set of locations. It offers flexible support and handling of cover art images, and features a cover art album browser and built-in downloader. Quasar is highly configurable and can be operated completely via keyboard, remote control, or touchscreen.