Record stores are expecting clogged aisles next week. On Monday, the compact disc version of the Beatles' "Sgt. Pepper's Lonely Hearts Club Band," the most celebated rock album of all time, goes on sale. The next day, Whitney Houston's new album--the follow-up to the biggest-selling debut LP ever--goes on the shelves. Capitol Records said that the initial shipment of "Sgt. Pepper" is the largest for any CD the company has released, including its other seven Beatles collections. Monday is the 20th anniversary of the release of "Sgt. Pepper." Arista's initial shipment of 1.5 million to 2 million "Whitney" albums figures to be just the beginning, since 1985's "Whitney Houston" sold 13 million copies worldwide. "I Wanna Dance with Somebody (Who Loves Me)," the first single from the album, has moved to No. 18 on Billboard's pop singles chart after three weeks. The song was written by George Merrill and Shannon Rubicam, the team responsible for her earlier No. 1 single, "How Will I Know."