The reason why you can do that is because an O-1 petition can be filed through an agent petitioner, which allows you to work with multiple employers and different projects throughout your O-1 validity period.
O-1B Petitions filed with an Agent
If you have filed with an agent petitioner, you can add additional performances and engagement to your petition. Even if those new additional performances and engagements weren’t included in your original itinerary.
It’s important to remember that the additional employment needs to be in your field of endeavor. For example, if you were filed as a performer then you cannot accept work as a director. Directing is not analogous to performing, they’re not the same thing.
This means that that future additional job of directing would be potentially considered a violation since it is not in the field of endeavor, which was discussed in your original I-129, or in your original petition.
O-1 Petition filed with a Single Employer
If your O-1 was filed with a single employer, then you cannot add additional performances and engagements. Work outside of the employment defined in your O-1 can potentially be considered a violation of your O-1 Status.
In order to accept new employment, you will need to file an amended O-1 petition as this would be considered a material change to the original O-1 petition.
Filing an Amendment: Material Change
A “material” change to your role would require an O-1 amendment. If there is a major change in your job duties from the duties listed in the O-1 petition, or if you change from working full-time to part-time, you add or change employment then you may possibly need to file an amended petition.
Therefore, it is extremely important to consider your options when deciding to file with an agent versus a single employer.