How to edit a cd track

There are many programs that create and edit MP3 files, and many of them are broken. As a result, many MP3 files have various issues, ranging from values that are not standards-conforming but that are tolerated by all players and tools (so they look perfectly fine to the end user) to files that play correctly only on some players or even cause players and tools to crash. Many of the tools are quite tolerant of errors in an MP3 file, but some are less so. Also, there are reasons to change a file even if it technically doesn't have errors; for example you may want to add the picture from the album cover, or the lyrics.

What is MP3 Diags and what does it do?

In a few words, MP3 Diags is a GUI-based application that allows end-users to identify issues with their MP3 files, fix some of the issues and make other changes, like adding track information. It also lets you "look inside" an MP3 file.
Unlike some programs that are designed to deal with a single topic (like fixing VBR headers or adding cover art), MP3 Diags is a one stop solution that identifies more than 50 different issues in MP3 files and provides the means to fix many of them (well, not everything is fixable; you can't make a 64kbps file sound like a 256kbps one.)

Some of the more important issues that are found:

•     broken tags / headers / audio

•     duplicate tags / headers

•     incorrect placement of tags / headers (ID3V2, ID3V1, LAME, Xing, ...)

•     low quality audio

•     missing VBR header

•     missing track info / cover art

•     broken track info / cover art

•     missing normalization data

•     character encoding issues (for languages other than English)

Some of the fixes and changes that MP3 Diags can do:

    Adding / fixing track info, including album cover; information can be retrieved from several sources: Internet, clipboard, file name, local files, and (obviously) keyboard
    Correcting files that show incorrect song duration
    Correcting files in which the player cannot seek correctly
    Converting characters for non-English names
    Adding composer name to the artist field, for players that don't handle the composer field
    Renaming files based on their fields
    Changing word case for track info