Enchanting tones and words I couldn’t understand filled the crispy air at the backyard of 190 Jefferson St. Sarah Cline as Electra sang in Greek so beautifully and urgently onstage, I found myself transported for several short minutes to Athens observing an ancient tragedy drama again and again. Director Ariel Kline’s instructions to the actors made my and my mind land back in Bushwick, where Envelope Ensemble has been rehearsing Electra by Euripides (adapted by Adrienne Kennedy) for weeks.