Lady Gaga and Tony Bennett, bridging a 60-year age gap to form one of music’s unlikeliest pairs, launched a jazz album on Monday that let the pop diva put aside her wacky* image to sing sweet harmonies with the elder statesman of cool.

    “Cheek to Cheek,” on sale yesterday after a launch concert in the ornate* Renaissance setting of the Grand-Place in Brussels, features jazz standards by Cole Porter, Duke Ellington and others a distant world away from Lady Gaga’s 21st century.

    “When I began writing music for the music industry, I became known as the quirky girl from downtown New York,” she told a news conference at the 15th-century city hall. “So I tailored my music to be that way, to get noticed, to be able to travel more and play more shows,” said the 28-year-old artist.

    But swathed in blue velvet with a 2-meter train, Lady Gaga this week was more 1950s Hollywood star than queen of MTV in 2014 — although still easily young enough to be Bennett’s grand-daughter.

    Once again, Lady Gaga kept it simple, sticking to a glittery gold cocktail dress and refraining* from any of the costume changes that her live performances are known for.

    For about 30 minutes, the two performed some of the highlights of the album, from the upbeat duet “It Don’t Mean a Thing” to Lady Gaga’s solemn solo performance “Lush Life.”(SD-Agencies)