English doesn’t have a grammatical gender as French, German and many other languages do. "Le crayon" (French masculine) and "la table" (French feminine), for example. English speakers might consider it peculiar to think of a crayon as masculine or a table as feminine. On the other hand, stereotypical gender conventions probably make it easy to envisage a rose as feminine. And instrument is a common noun so is naturally suited to being gender-neutral, though we could probably think of types of instrument that we would classify as feminine or masculine! This is the result of social conditioning rather than distinctions being hardwired into our language.