Peabody Opera presents a double bill in Friedberg Hall: Ralph Vaughan Williams’ Riders to the Sea and Missy Mazzoli’s Proving Up. This pair of one-act operas, sung in English, feature striving families in the 1800s trying to better their fates in the face of nature’s formidable obstacles. Grace Touhill performed as Cathleen in Riders to the Sea on Friday & Sunday in this early 20th-century opera, which takes place on the desolate Irish island of Inishmaan where fishing families face the continual threat of life on the sea.