source->mark_streaming_midi_write_started (source_lock, note_mode());
for (Evoral::Sequence<TimeType>::const_iterator i = begin(TimeType(), true); i != end(); ++i) {
source->mark_streaming_midi_write_started (source_lock, note_mode());
for (Evoral::Sequence<TimeType>::const_iterator i = begin(TimeType(), true); i != end(); ++i) {