CBS is adding some Grammy muscle to its November sked.The Eye has ordered “My Night at the Grammys,” a two-hour special linked to the kudocast’s 50th anniversary. Spec will feature 25 memorable performances from past Grammy shows, with viewers determining the playlist via an online vote. Interviews with the “winning” artists will air in conjunction with the performances. Voting will take place via MyNightattheGrammys.com through Oct. 7. The Recording Academy has posted clips from 50 past perfs and will let audiences narrow the field in half. CBS has slotted “My Night at the Grammys” for Nov. 30, from 8-10 p.m. Ken Ehrlich and John Cossette produce.