a violin with excellent tone的用法和样例：
- The SP20 is a professional diatonic harmonica with excellent tone color and playing performance, which is worth owning.
- One day, a beggar comes to the door with a violin.
他一气之下决定让his daughter marry a beggar.
- There are four strings on a violin.
- They were akin to a violin with only one string and no fingerboard, capable of playing only one note (ignore for the moment that musical notes are much richer than pure tones).