Aretha Franklin canceled her scheduled appearance at Whitney Houston's funeral service in New Jersey yesterday afternoon ... but was well enough to perform at Radio City Music Hall that night.

Aretha said she had been suffering from leg spasms and wanted to rest up for her show, rather than travel for the funeral. She released a statement, saying in part, "heart goes out to my dear friend Cissy, Dionne, Bobbi Kristina and the rest of the family. May God keep them all."