A Network Musical Performance (NMP) occurs when a group of musicians, located at different physical locations, interact over a network to perform as they would if located in the same room. In this paper, we present a case for NMP as a practical Internet application, and describe a method to ameliorate the effect of late and lost packets on NMP. We describe an NMP system that embodies this concept, that combines several existing standards (MIDI, MPEG 4 Structured Audio, RTP/AVP, and SIP) with a new RTP packetization for MIDI performance. We analyze NMP experiments performed on CalREN2 hosts on the UC Berkeley, Stanford, and Caltech campuses.