On the last day of July, 2013, I saw and heard an unforgettable performance in Tanglewood’s Seiji Ozawa Hall. Mark Morris had directed Benjamin Britten’s Curlew River for a cast of Tanglewood Fellows and paired it with his 1989 visualization of Henry Purcell’s opera Dido and Aeneas, performed by the Mark Morris Dance Group and the MMDG Musical Ensemble. The last sentence of my review was this: “I wish I could see it again this very minute.” I’ve had to wait three-and-half years.