Foreign nationals are generally allowed to attend a conference/festival as a “visitor.” This means if you are eligible to enter the U.S. under the Visa Waiver Program (“ESTA”) that is sufficient. If you are not eligible to enter the U.S. under the Visa Waiver Program (“ESTA”), you will probably need a B-1 or B-2 visa.
Visa Waiver Program
The Visa Waiver Program enables most citizens or nationals of participating countries* to travel to the United States for tourism or business for stays of 90 days or less without obtaining a visa. Travelers must have a valid Electronic System for Travel Authorization (ESTA) approval prior to travel and meet all requirements explained below.
Eligible for VWP:
Andorra
Australia
Austria
Belgium
Brunei
Chile
Croatia
Czech Republic
Denmark
Estonia
Finland
France
Germany
Greece
Hungary
Iceland
Ireland
Israel
Italy
Japan
Latvia
Liechtenstein
Lithuania
Luxembourg
Malta
Monaco
Netherlands
New Zealand
Norway
Poland
Portugal
San Marino
Singapore
Slovakia
Slovenia
South Korea
Spain
Sweden
Switzerland
Taiwan*
United Kingdom**
**To be eligible to travel under the VWP, British citizens must have the unrestricted right of permanent abode in England, Scotland, Wales, Northern Ireland, the Channel Islands, and the Isle of Man.