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).
... of the resistance were Abwehr, Gestapo, Sicherheitspolizei[?] and Wehrmacht but those were just the German part. In addition to threat of paid informants, there was ...