For the world’s elite, rare musical instruments are more than artistic treasures—they’re sound investments harmonizing passion, history, and jaw-dropping returns. With Stradivarius violins selling for 20million+∗∗andguitarslikeKurtCobain’sFenderMustangfetching∗∗20million+∗∗andguitarslikeKurtCobain’sFenderMustangfetching∗∗6 million, this niche market crescendoed…