The term 'organ stop' refers to a device used in pipe organs to control the flow of air and produce different sounds. The crossword solutions for this term include OCTAVE (6 letters), OBOE (4 letters), clarabella (10 letters), VIOL (4 letters), quint (5 letters), scharf (6 letters), salicet (7 letters), and diapason (8 letters). OCTAVE is a musical interval that spans eight notes, OBOE is a woodwind instrument, clarabella is a type of organ stop, VIOL is a bowed string instrument, quint is a five-note musical interval, scharf is a type of organ stop, salicet is a type of organ stop, and diapason is a type of organ stop.