[silence] The first mesostic?

[Ben Basan]

Hi All,

I'm wondering if anyone out there would know when Cage first started  
writing mesostics. I'm getting a lot of conflicting information.  
Marjorie Perloff indicates that the first one was in 1970 . I think  
she's basing this on Cage's recollection of writing them in or around  
Endwin Denby's loft. But then James Pritchett suggests that Cage  
started writing them before the late 60s (no real start date given)  
although only for friends. Pritchett's account must be more accurate  
than Perloff's based on what I do know (such as the graphical  
mesostics starting from 1967 up on UBU!).  However, I haven't really  
been able to locate anything more precise than 'before the late 60s.'  
What I am trying to suss out here is roughly when Cage's interest in  
applying procedures/ constraints on his writing began.

Thanks!
Ben