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).
... and Catherine of Aragon, who was his aunt.
As Holy Roman Emperor, he called Martin Luther to the Diet of Worms in 1521, promising him safe conduct if he would appear. ...