+ framepos_t _last_ev_time_frames;
+ /** end time (start + duration) of last call to read_unlocked */
+ mutable framepos_t _smf_last_read_end;
+ /** time (in SMF ticks, 1 tick per _ppqn) of the last event read by read_unlocked */
+ mutable framepos_t _smf_last_read_time;