Fryderyk may have had some piano instruction from his mother, but his first professional music tutor, from 1816 to 1821, was the Czech pianist Wojciech Żywny. His elder sister Ludwika also took lessons from Żywny, and occasionally played duets with her brother. It quickly became apparent that he was a child prodigy. By the age of seven Fryderyk had begun giving public concerts, and in 1817 he composed two polonaises, in G minor and B-flat major. His next work, a polonaise in A-flat major of 1821, dedicated to Żywny, is his earliest surviving musical manuscript.