At the bottom of each individual forum there is a key
This key states that if you have posted in a thread, an arrow appears next to the speaker icon down the left hand side. Hey presto! You can see at a glance if you have reviewed a song or not.
This key tells me which thread I have posted in, and which I have not
Look for the small grey speaker symbol which runs down the very left hand side of the forum. It is two columns to the left of the Subject/Author column.
The key explaining this is at the very bottom of each forum page in a dark grey box. (It is not on the homepage, just on each forum page.... reviews, lyrics, the bar, etc)
If there is a small, white arrow over the speaker, you have posted in that thread.