Los Angeles, Jan 23 : Legendary singer Madonna celebrated her fourth child's birthday with a touching tribute. The 'Vogue' singer, 65, shared a photo montage of her daughter Chifundo "Mercy" James for her 18th birthday. The sweet montage was set to background music of Mercy gracefully playing a rendition of Erik Satie's 'Gnossienne No.1' on the piano, reports 'People' magazine. The 'Material Girl' singer began her birthday message in the Instagram caption, 'Beautiful Chifundo James! you're 18 years old today!! Beautiful Mercy James. You're already a young woman! Beautiful African Queen!! You Surprised all of us'. As per People, Madonna went on to share how Mercy has been the 'quiet', 'gentle', 'shy' and 'stoic' sibling and "never" wanted "to draw attention" to herself. 'Always Humble and Kind, Always the first one to say thank you. To clear the table after dinner! To Come and Hug me and say how much you appreciate something,' Madonna shared. 'And Always the most Responsible. I am really astounded by the woman you have become. Poised and radiant. Skilled and Soulful. A True artiste.' Madonna next praised Mercy's musical abilities. 'That hand that was once frozen in your mouth as a child -now makes magic happen when you play the piano," she wrote. "Whether it's Erik Satie or Chilly Gonzales. To hear you play Chopin every night in my show with such confidence is such a thrill.' She then applauded Mercy's talents behind a camera. 'Nothing gives me greater pleasure than to watch you grow. You really are A wonder,' Madonna wrote of her daughter. 'Wishing You the happiest of Birthdays! The happiest of everything -- because you deserve it.' 'Even though we both hate shellfish, the world is your Oyster. She is waiting for you to devour it. To eat it whole!!! To Slay it,' concluded the singer. /IANS