A treaty usually shields cross-border income, except for the one article written specifically to catch performers.
A double-tax treaty is the rulebook two countries agree on for splitting the right to tax the same income. Its default instinct is generous to the visitor: most business profits are taxable only at home, and are often taxed at a sharply reduced rate (sometimes nil) in the country where they arise.
So far, so good for a touring or licensing client. Then comes the trap. Almost every treaty contains a special entertainers and sportspersons article (usually Article 17 in the OECD model) written precisely to deny performers that shelter. It hands the taxing right on a live performance back to the country where the show happens, regardless of how short the visit is or whether the artist has any local presence.
That is the counter-intuitive shape of this module. For a or songwriting client, the treaty is a tool that reduces foreign tax. For a performing client, the most important article in the treaty is the one that removes the relief the rest of the treaty would have given. The adviser's job is to know which article governs each stream, and to do the paperwork that unlocks the reduced rate where one is actually available.
Everything below (article numbers, rates, thresholds) is illustrative and jurisdiction-specific. Treaties differ article by article; verify against the actual treaty in play.