Quote Originally Posted by JonR
AFAIK, yes - at least the "CTo7" is a classical abbreviation of "common tone diminished".

Check stevel's post in this thread for a qualified classical viewpoint on the cto7 at least:
http://www.thegearpage.net/board/ind...water.1677901/

The "leading tone 7th" term I got from a jazz theory book, but "leading tone" and "vii" are certainly classical terms.

However, I should point out that the author (William Russo) used the term "leading tone 7th" to refer to the vii chord of a major key, the m7b5 chord. This is despite the fact that - as he was surely well aware - m7b5 chords are used almost always as ii chords (supertonics) in minor keys, almost never as vii in major keys. More often a major key will borrow the vii chord from the minor key, the full dim7; which he called simply "diminished 7th" - a name which says nothing about its function. (I guess that's sensible because a dim7 can have three different applications.)

So until I get corrected by a properly trained classical person, I'll continue to call that particular application of a dim7 a "leading tone 7th".
"viio7" is of course also suitable, as well as being shorter and possibly more correct! (The only problem there is verbalising it: "Seven diminished 7th"?)
viim7b5 - I is common in classical harmony IIRC... The m7b5 was seen as an incomplete V9 chord... So it does get used in that situation