People who comment on Mediocre online tend to be divided between those who love it and those who hate it, and those who hate it will sometimes point out that Ximena Sariñana’s career, first as an actress, now as a singer, has received substantial help from her father, a director and producer of Mexican movies. Don’t let that put you off. Sariñana’s voice can’t withstand the comparisons to classic black American singers that the Those Who Loves like to throw at it, but her pop-soul tone has an indomitable spine, and parts of “Un Error” prove that she can push toward Aretha Franklin territory if she wants to. Most of the time she doesn’t. She likes contemporary ballads, touches of swing, and country, and jazz, and rock, and bits of urban urgency. Mediocre could be her Come Away with Me.