Each theme answer features a different anagram of HORSE: OSHER, ERSHO, and EORSH. Congratulations to Ed Sessa making a USA Today crossword debut! Thank you, Ed, for this entertaining puzzle.
ENCORES (40D: Bonus songs artists come back on stage to perform) This feels like a bonus in today's RIHANNA-themed puzzle. Perhaps "UMBRELLA" is the main performance today and "SOS" is the ENCORE – or ...