The word “diva” gets thrown around way too much these days. It started last year, when VH-1 hosted the execrable “Divas Live,” featuring the lackluster talents of Celine Dion, Mariah Carey, and…Shania Twain? If Shania Twain’s a diva, then Madeleine Albright is a prima ballerina. It only got worse when Entertainment Weekly and People magazine both devoted recent cover stories to the goings-on of the “new breed” of divasa bunch of fussy, ill-tempered toothpicks like Calista Flockhart and Jenna Elfman. To be truly worthy of the d-word, you’ve got to have talent, perseverance, and enduranceyou’ve got to pay your dues. (And I don’t mean marrying your manager, Mariah.) Patti LaBelle learned all about divadom long ago, first as lead singer of girl group LaBelle, then as a Grammy-nominated solo artist. She’ll be giving lessons at a pair of performances, tonight and tomorrow, with Gerald Levert, at 8 p.m. at DAR Constitution Hall, 18th and D Sts. NW. $55. (202) 432-7328. (Dan Avery)