Final answer:
The 'sympathetic tone' in musical instruments like violins relates to a warm, rich, and emotionally resonant quality that develops over time as the instrument is played.
Step-by-step explanation:
The sympathetic tone referred to when discussing instruments like the barrel-organ or violin suggests a warm, rich quality of sound that develops over time from being played. The timbre, or tone quality, of a musical instrument is indeed a facet of its overall character and is highly subjective. Different materials, designs, and the wear over time can alter the harmonic content of an instrument and add to its timbres, often contributing to a fuller, more resonant sound as perceived by listeners. The term sympathetic in this context underlines this pleasant, emotionally resonant quality that can enrich the musical experience.