When you have musicians in the family, it becomes a necessity. You buy houses you may not even like just because they have more room. How else can anyone survive the nightly onslaught of piano, flute, guitar, singing, clarinet and keyboard? Also, at one point DBH taught singing at weekends to bring in extra money. DS aged 6 months deeply resented the singers interrupting his teatime, showed us the power of his own voice and very successfully drowned those of the poor pupils!
Our current music room is 'outside'. It's a long row of outhouses, housing DBH's study, the musicroom which is large and also houses DS's computer and a bed for him for when the GCs are sleeping in his room, a small utility area housing several freezers and my lean-to greenhouse/pottingshed. Which contains my tumble-dryer. The house isn't large, those extra rooms out there make all the difference when DD and family come to stay for the week. The music room becomes an extra playroom.