Officials say a non-New Jersey resident who attended the May 15 concert was infected with the disease.
They are urging individuals, especially parents, health care providers and caregivers, to be aware of the symptoms, and to ensure they are up to date with the measles, mumps and rubella shots.
Measles symptoms include a high fever, cough, runny nose, watery red eyes, and a rash that usually appears between three and five days after symptoms begin.
The Department of Health recommends that anyone who suspects they were exposed to the virus on the date and location of the concert, or are ill, call a health care provider before going to any medical office or emergency department.
They say a potentially exposed person, if infected, could develop symptoms as late as June 6.