From: Benjamin Tubb To: Roland JV/XP Mailing List Subject: [jv1080] Optimal Tempo/PPQN Values for Recording Date: Saturday, January 17, 1998 4:24 AM + List Help : finger: jv1080@emccta.com, web: http://www.emccta.com/~jv1080 + List Admin: mvitek@emccta.com, http://www.emccta.com/~mvitek Optimal Tempo/PPQN Values for Recording Since the realime recording of MIDI event data is directly affected by three factors (MIDI's transmission speed, Tempo and PPQN delays), the following relationships made with such limitation constraints in mind, offer optimal sysex, running status, and typical 3-byte Note On/Off recording of live performances, with the recommendation that only the PPQNs factored by 2 and 3 (such as 96, 192, 384, and 768) only be used to minimize quantisation errors of human performance nuances. I do not recommend using PPQNs of 120, 240, 480 or 960 because of the "inhuman" feel which the factor of 5 introduces to such quanitisized recordings. For sysex events, and especially MIDI Sync 1-byte events, where the maximim tick delay is .3125ms, a Tempo of 250 at a PPQN of 768 is optimal. For Running Status 2-byte events, such as a instrumental solos on one MIDI channel, where the clock tick delay is .625ms, either a Tempo/PPQN of 125/768 or 246/384 are optimal. For typical 3-byte Note On/Off events, as in general multichannel data, where the clock tick delay is .9375ms, either a Tempo/PPQN of 83/768 or 166/384 are optimal. ------------- Benjamin Tubb AIM: brtubb brtubb@cybertron.com http://home.cybertron.com/~brtubb "Music creates order out of chaos; for rhythm imposes unanimity upon the divergent, melody imposes continuity upon the disjoin- ted, and harmony imposes compatibility upon the incongruous." - Yehudi Menuhin, from "Theme and Variations"