Who called from 4155516242

Me too.  I call back and it says the mail box at the extension is full.

Used the vm message to route into the system for the operator associated with that number - and got "San Francisco Opera".

Yes, it is SF Opera. i get called too.

Yup.  SF Opera.  I got their sales office on the line and had them remove my name from their telemarketing list.  The rep seemed nonchalant about their policy of never leaving a message.  Strike one against SF Opera.

Have been getting calls from this number too.