Nick JonasAt his Friday night solo show at New York City's Beacon Theater, Nick Jonas took time to bring out a pair of very special guests, proving the formula that if 2,000 teenage girls scream at X decibels for one Jonas Brother, they will risk hoarseness -- and the deafness of their parents -- to screech at 3X for three Jonas Brothers.

"There are two people I want to share this moment with," Nick said midway through the piano ballad 'Black Keys,' a tune he played without help from his new backing band, the Administration.

Out strolled Joe and Kevin, both of whom had been watching from a VIP area on the left side of the theater, and the Beacon shook with screams. For a few minutes, the elder Jonas brothers did little but look pretty and drum up applause for their 17-year-old kid brother, the singer, songwriter and multi-instrumentalist said to be the architect of the JoBros sound.