You're right. Before WLS went Top 40, WJJD was the daytime option. At night we could hear some Top 40 on WIND especiallyI could be mistaken, but I think all of the Westinghouse O&O stations were at least "dabbling" in top 40 during the late 50s and early 60s. When I was growing up, my parents' favorite station was WIND, which was basically what Billboard magazine called "Adult Contemporary" during the day, but rocked a little harder at night. I think WOWO, KDKA, and WBZ were variations of the same formula. I listened to WBZ quite a bit during the early and mid '60s, and they were definitely rockin' at night with the likes of Bruce Bradley and Dick Summer. And I always considered WOWO a top 40 station. OTOH, by the mid 60s, WIND was basically the same "Adult Contemporary" day
on Sunday nights when Milo Hamilton played the "Top 21".