Rachel Resnick, author of “Love Junkie,” discusses her book with the audience at B’s Mountain of Books during the last session of the Idyllwild Authors Series.

Classic rock ’n’ roll revs the dancin’ The Diamonds, a 50s and 60s Canadian rock and roll quartet, will open the 20th Annual Idyllwild Summer Concert Series (ISCS) on July 11. The group is well-known for several songs, including “Little Darlin,” “Silhouettes” and “The Stroll.” They are definitely classical rock and roll. The Diamonds had 16…