Celine Dion's music has been a firm fixture in the industry for decades, and on Monday the My Heart Will Go On singer had an important milestone to mark.MORE: Celine Dion looks radiant as she celebrates very happy newsTaking to Instagram, the Canadian singer shared a montage of photos of her singing on stage throughout the years, from childhood to recent times, as she marked her 40th anniversary in the industry.She wrote: "Celebrating 40 years of an amazing career!" which quickly sparked