Hi,
I am an opera singer, who pays tax in Italy. I am now coming over to the US to perform one concert. The fee is beneath the sum of 10.000 USD and I won't have other jobs in the US this year. In order to trying to avoid an immediate deduction of the withholding tax I wanted to fill out the IRS form 8233 and refer to the US/Italy tax treaty.
Would you happen to know, which article of the treaty is the correct one to refer to in my case ?
And, what do I do, if my employer does think I am NOT right by filing this form and does therefore not want to sign it and pass it on to the IRS ?

Cite Article 17(1)(a) of the U.S.-Italy Tax Treaty, text of which is below:

1. Income derived by a resident of a Contracting State as an entertainer, such as a theatre, motion picture, radio, or television artiste, or a musician, or as an athlete, from his personal activities as such exercised in the other Contracting State, which income would be exempt from tax in that other Contracting State under the provisions of Articles 14 (Independent Personal Services) and 15 (Dependent Personal Services), may be taxed in that other State, if:

(a) the amount of the gross receipts derived by such entertainer or athlete, including expenses reimbursed to him or borne on his behalf, from such activities exceeds twenty thousand United States dollars ($20,000) or its equivalent in Italian currency for the fiscal year concerned;