Providing temporary use of online non-downloadable computer software for use by disc jockeys in mixing, synchronizing, and performing music; for music collaboration, namely, enabling multiple users to collaboratively mix and perform music together in real time via computer networks; for analyzing music data, namely, beat position, tempo, and waveform information; for setting and managing cue points and loops in music recordings; for managing music libraries and playlists; and for recording, transmitting, and playing back audio