The 16rpm speed was actually 16 2/3rpm, which is exactly half of 33 1/3. Probably not a coincidence. If the 45rpm and 33 1/3rpm systems were, in fact, developed by different companies, it is an interesting coincidence that 33 and 45 add up to 78. Ain't numbers fun?

BTW, I have an old Monty Python album with 2 grooves on one side, making it a 3-sided record. I think it was "Matching Tie and Handkerchief," but I'm not certain. On the one side, you would get different material, depending on exactly where the needle set down. Good for freaking out stoned friends.

jeffp