For ID3 tags you can remove a frame with delall. For example:
>>> print audio.pprint()
TPE1=Agalloch
TALB=The Mantle
TRCK=1/9
TIT2=A Celebration For The Death Of Man...
TCON=Metal
>>> audio.delall('TCON')
>>> print audio.pprint()
TPE1=Agalloch
TALB=The Mantle
TRCK=1/9
TIT2=A Celebration For The Death Of Man...
For deleting the FLAC metadata (I do not have any FLAC files to test this on), I have a good feeling about:
>>> del audio['tag_to_delete']
Since the help documentation has:
| __delitem__(self, key)
| Delete a metadata tag key.
|
| If the file has no tags at all, a KeyError is raised.
You can read more about the delitem magic method here: http://www.rafekettler.com/magicmethods.html