Complex sentence: Later, she sreceived only private lessons over the course of eighteen months with organist E. Thuner, but in 1915, she was afforded the opportunity to audition as an independent student by way of the organist exam at the Music Academy.
Split into simpler sentences: Later, she received private lessons over the course of eighteen months with organist E. Thune. In 1915, she was afforded the opportunity to audition as an independent student by way of the organist exam at the Music Academy.