Don't care for Adele's overdramatic singing at all. When she first came on the scene though, 'Rolling in the Deep' and 'Rumor has it' were both fantastic songs. After that...
piano guys even did a cover of rolling in the deep
https://www.youtube.com/watch?v=lUjWJSnGVB0
i like their mash of Bach and Secrets
https://www.youtube.com/watch?v=mJ_fkw5j-t0
the cello they used in guns and roses song is pretty cool
https://www.youtube.com/watch?v=D7SqPiohNDU
That’s part of it but I think it refers to an extended exclusive run of performances like a Broadway play. It’s offered to big artists who may have gotten tired of touring and its rigours. The artist instead resides in Vegas at the hotel where shows are held and everyone travels there instead of the artist touring to where everyone lives. You might say Wayne Newton started this by basically living in Vegas and becoming the King of Vegas by mostly performing just there. Yes he did tour on occasion but Vegas was home for him performance wise and literally.