Bobby what is with the letters on your drum heads?

New to this, haven't been on a forum since Cigar Aficionado shut theirs down about eight years ago .....

 

Anyhow, don't know how to search for the answer but anyone have the answer?  This old cat would love to know.  

 

Thanks y'all.

 

Keith From Canada

Comments
In an attempt to reduce spam, comments on content older than one year cannot be posted.