Simplify the following text for a Grade 6 native English-speaking person.
Original: ( His nephew-by-marriage , Leon BoÃ `` llmann , became another fine organist and composer for the organ , whose death at the very young age of 35 was a severe loss to French music . )
Simplified: His nephew-by-marriage , Leon BoÃ `` llmann , became another fine organist and composer for the organ . He died at the very young age of 35 .