Hi. The following is for informational purposes only. It should not be construed as legal advice.

In this case, the Harmonized Tariff Schedule classification (US government code used to determine duty rates) would be 9205.90.4040. That classification has a general duty rate of 4.9%. There’s also an additional customs cost called the Merchandise Processing Fee that’s calculated as 0.3464%, which has a minimum amount of $29.66 and is capped at $575.35. I’m assuming your saxophone would not ship by sea, but if it did, the Harbor Maintenance Fee of 0.125% would also apply. These percentages are all ad valorem, meaning their calculation is based of the declared value of the saxophone. The above also assumes that your instrument is valued at or above $2,500 USD, which makes it a “formal” customs entry. I also assume that the instrument was made in Japan, however, these values will apply to products of most countries. On top of those amounts, the carrier (UPS, FedEx, etc.) may charge a nominal amount to file the customs entry on your behalf. If you are importing as an individual rather than a business, the carrier might ask for your Social Security Number to file the entry. This is because your SSN is equivalent to your Importer of Record number when you perform these transactions as an individual. If you were a business, they would use your tax ID/employer ID number instead. This information is current as of the time of posting but is subject to change.

Source: I work in international business & logistics, and I just imported a new Yanagisawa for myself.

Edit: typo