Kid3 is a powerful audio tag editor for KDE with support for formats like MP3, Ogg/Vorbis, FLAC, MPC, MP4/AAC, MP2, Speex, TrueAudio and WAV. Kid3 allows you to edit common tags over multiple files as well.
The latest version, 3.1, brings many features, bug fixes and improvements. According to the changelog, here are the changes in 3.1:
+ Support for synchronized lyrics and event timing codes.
+ Import and export of LRC (synchronized lyrics/Karaoke) files.
+ Find and replace strings in tags and file names.
+ Display details and sort columns in file list.
+ Open and Open Containing Folder file list actions.
+ Support Ogg and Opus cover art.
+ Export format CDRDAO TOC for CDs with CD-text from WAV tags.
+ D-Bus command expandFileList() to expand the whole file list.
+ Updated Czech, Finnish, Estonian translations.
+ GUI and usability, keyboard navigation.
+ Restore Quick Access Tags settings properly.
+ Support tags from file name with 2 character extensions (e.g. ???.wv???).
+ Keyboard shortcuts settings with Mac OS X 10.9.
+ Build without Phonon.
+ Fingerprint decoding and resampling with libav.
+ D-Bus command expandDirectory().
Installing Kid3 3.1 in Ubuntu 14.04
To install 3.1 in Ubuntu, you will have two install separately two DEB packages provided on the homepage. First, you will have to install the core libs package (direct link here), and then the Kid3 package (direct link here). Make sure to download the corresponding packages for your architecture, I provided links for 32-bit here.
Once downloaded, either double click them in this order (first the core libs and then the Kid3 package), or open a terminal and type:
sudo dpkg -i kid3-core_3.1-0trusty_i386.deb
sudo dpkg -i kid3_3.1-0trusty_i386.deb