“Writing a full-length opera for a major company is like running for president: Blow it and you’ll never get a second chance.” As a result, many composers are understandably cautious about even approaching the form, and many opera companies that want to put on new works can’t find anyone willing to write them. But a program at Toronto’s Tapestry New Opera Works has been churning out new material for a decade, although admittedly in five to ten-minute chunks. The composer-librettist labs, in which participants must create a new short operatic work every day, are designed “to discover as quickly and cheaply as possible who is cut out to make operas and who isn’t.”