Sometimes you just can't help but sing along. In North Carolina, Daria Gavrilova broke into some Bruno Mars while supporting Team Australia from the bench. Gavrilova stepped in for the fourth rubber of the tie, falling to Danielle Collins in three sets.

The quarterfinal would go to a deciding doubles match, which Australia won thanks to Ashleigh Barty and Priscilla Hon beating Collins and Nicole Melichar. 

All the way over in Switzerland in Group II play, Timea Bacsinszky also couldn't help herself.

The singing seemed to be good luck as Switzerland took out 3-1 behind two wins from Belinda Bencic.

The Fed Cup semifinals are set with Australia taking on Belarus and Romania playing France in April. Belarus eased past Germany 4-0 and France dispatched Belgium 3-1. Romania's tie against the defending champion Czech Republic went down to the doubles match, just like Australia's win over the United States.