7-9:30 pm, July 31. Check-in begins at 6:30 for those participating in final “Summer Sings” concert — Bach’s “St. John Passion” (abridged), conducted by Noah Horn of Wayne State University. Singers are invited to these choral reading sessions. They “feature no-audition, no-performance evenings of memorable music-making.” At University of Michigan, Walgreen Drama Center’s Stamps Auditorium, 1226 Murfin, Ann Arbor. $5; includes refreshments and scores may be borrowed. Info: ums.org.