Abstract: A stringed musical instrument, in particular a double bass, having a resonating body of narrow elongate shape, a neck secured to this body and strings extending across the body and neck and across a bridge supported on the front plate of the body. A transverse sound-beam inside the body divides the latter into two separate resonating chambers of unequal size which are acoustically connected by a through-hole in the sound-beam. Below the bridge a bore extends through the body front plate and into the sound-beam to open into the connecting hole of the beam and an electrical pick-up element extends through this bore between the lower side of the bridge and a vibration plate mounted in the connecting hole.