Experiments in Opera, the new collective founded by composers Jason Cady, Aaron Siegel, and Matthew Welch, presents its Spring Series on May 10 + 11 (Thursday and Friday) at Roulette in Brooklyn. Four new operas will be heard in workshop performances over the two evenings. The May 10 program features a complete semi-staged, multi-media performance of Cady’s Happiness is the Problem, plus a semi-staged, work-in-progess presentation of To Scale by the creative trio known as Cough Button, and a concert excerpt from Siegel’s Brother Brother. May 11 will be devoted to a semi-staged production of Welch’s Borges and The Other,