I just noticed that there are still over 1200 from 5152 Chinese songs cannot be decoded. In all those songs, the key length could not be determined. Now I've replaced the algorithm. Instead of searching for pattern (with 2 attempts), I try to find the first character of the song title.
Now, the key lengths of all Chinese songs are found. I hope that there is no side effect on English songs.
Phuoc Can HUA
toc2db.zip........................
www.folksfun.com
........................