Impressive attention to detail basasfan, from 1970 to 1975 the Carpenters and Elton ruled the Top 40 charts. I wonder if Elton looked upon Karen and Richard with disfavor after the firing of his good friend Neil Sedaka in 1975? The only time I remember their paths crossing was in 1980 during the taping of Olivia's Hollywood Nights special where Karen and Elton were guests. Maybe they had some encounters at the Grammy Awards or met backstage during the Carpenters UK tours.
I just finished reading his autobiography.Not a Sedaka fan at all. Sedaka tried to act like he was the headliner, not the Carpenters. I like Elton but he can be a diva, I have seen his documentary Tiaras and Tantrums. He has been known to go off on people.