Hey ExJL, welcome to AudioCircle!
Imo, both of those tracks are disco, not jazz. But these days 'jazz' is a catch all for anything not quite mainstream. Rumer's voice is very beautiful by modern standards. Thanks for the tip, I'll check out her other stuff. If you like her, check out Katherine McPhee's albums, similar top notch vocals as Rumer, maybe a tad more 'jazzy' (in the modern meaning of the word.) Traditional female jazz singers from the jazz era definitely worth checking out too. Billie Holiday, June Christy, Sarah Vaughan, etc.
I think Bing Crosby was the most famous jazz singer of all time. He sang in the 30s, 40s and 50s when jazz was pop music. He was also a famous movie star.
Frank Sinatra was also more famous than Carpenters by singing real jazz arrangements in 40s, 50s and 60s, even after rock took over.
I do remember that Karen Carpenter was a drummer first and she didn't really want to sing but the money pressure pushed her into it. She looks stoned in that dancing video, making the song title seem very ironic. Even 30 years later they were still trying to appeal to the Bing Crosby "song and dance" fans.
Thanks for the post! Very thought provoking!