Complex sentence: After giving his first performance on May 10,1873 at the Atlantic Garden at age 15, he quickly began performing across the country in various bands and orchestra and was nickamed the "Boy Wonder".
Split into simpler sentences: After giving his first performance on May 10,1873 at the Atlantic Garden at age 15, he quickly began performing across the country in various bands and orchestra. At the age of 15, he was nickamed the "Boy Wonder".