An instrument is a concrete or abstract tool intended for a purpose other than mechanical work, in particular a refined one.
Musical instruments are devices designed to produce music, frequently by plucking or striking a string or bell or drum surface, or by forcing air to resonate (see wind instruments).
... Vronsky to the jealously of Dolly's sister Katarina (Kitty) whom he has previously been courting.
As the novel opens, Stiva's friend Levin has returned Moscow from ...